diff --git a/packages/one/src/cli/build.ts b/packages/one/src/cli/build.ts
index 2a767c5317..0fef0ab7b7 100644
--- a/packages/one/src/cli/build.ts
+++ b/packages/one/src/cli/build.ts
@@ -5,7 +5,7 @@ import { resolvePath } from '@vxrn/resolve'
 import FSExtra from 'fs-extra'
 import MicroMatch from 'micromatch'
 import type { OutputAsset, RolldownOutput } from 'rolldown'
-import { type InlineConfig, mergeConfig, build as viteBuild } from 'vite'
+import { type InlineConfig, mergeConfig, normalizePath, build as viteBuild } from 'vite'
 import {
   type ClientManifestEntry,
   fillOptions,
@@ -19,7 +19,7 @@ import { setServerGlobals } from '../server/setServerGlobals'
 import { getPathnameFromFilePath } from '../utils/getPathnameFromFilePath'
 import { getRouterRootFromOneOptions } from '../utils/getRouterRootFromOneOptions'
 import { isRolldown } from '../utils/isRolldown'
-import { toAbsolute } from '../utils/toAbsolute'
+import { toAbsolute, toAbsoluteUrl } from '../utils/toAbsolute'
 import { buildVercelOutputDirectory } from '../vercel/build/buildVercelOutputDirectory'
 import { getManifest } from '../vite/getManifest'
 import { loadUserOneOptions } from '../vite/loadConfig'
@@ -347,7 +347,7 @@ export async function build(args: {
   if (middlewareBuildInfo) {
     for (const middleware of manifest.middlewareRoutes) {
       const absoluteRoot = resolve(process.cwd(), options.root)
-      const fullPath = join(absoluteRoot, routerRoot, middleware.file)
+      const fullPath = normalizePath(join(absoluteRoot, routerRoot, middleware.file))
       const outChunks = middlewareBuildInfo.output.filter((x) => x.type === 'chunk')
       const chunk = outChunks.find((x) => x.facadeModuleId === fullPath)
       if (!chunk) throw new Error(`internal err finding middleware`)
@@ -356,7 +356,7 @@ export async function build(args: {
   }
 
   // for the require Sitemap in getRoutes
-  globalThis['require'] = createRequire(join(import.meta.url, '..'))
+  globalThis['require'] = createRequire(import.meta.dirname + '/')
 
   const assets: OutputAsset[] = []
 
@@ -426,7 +426,10 @@ export async function build(args: {
     // layout files start with _layout
     if (file.startsWith('_layout') && id.includes(`/${routerRoot}/`)) {
       // contextKey format is "./_layout.tsx" or "./subdir/_layout.tsx"
-      const relativePath = relative(process.cwd(), id).replace(`${routerRoot}/`, '')
+      const relativePath = normalizePath(relative(process.cwd(), id)).replace(
+        `${routerRoot}/`,
+        ''
+      )
       const contextKey = `./${relativePath}`
       layoutServerPaths.set(contextKey, output.fileName)
     }
@@ -469,10 +472,8 @@ export async function build(args: {
     }
 
     // resolve the full module path for this route
-    const routeModulePath = join(
-      resolve(process.cwd(), options.root),
-      routerRoot,
-      foundRoute.file.slice(2)
+    const routeModulePath = normalizePath(
+      join(resolve(process.cwd(), options.root), routerRoot, foundRoute.file.slice(2))
     )
 
     // find the server chunk containing this route
@@ -761,7 +762,7 @@ export async function build(args: {
 
     let exported
     try {
-      exported = await import(toAbsolute(serverJsPath))
+      exported = await import(toAbsoluteUrl(serverJsPath))
     } catch (err) {
       console.error(`Error importing page (original error)`, err)
       // err cause not showing in vite or something
diff --git a/packages/one/src/cli/buildPage.ts b/packages/one/src/cli/buildPage.ts
index d0402aceb9..08565c27d7 100644
--- a/packages/one/src/cli/buildPage.ts
+++ b/packages/one/src/cli/buildPage.ts
@@ -5,7 +5,7 @@ import { LOADER_JS_POSTFIX_UNCACHED } from '../constants'
 import type { LoaderProps } from '../types'
 import { getLoaderPath, getPreloadCSSPath, getPreloadPath } from '../utils/cleanUrl'
 import { isResponse } from '../utils/isResponse'
-import { toAbsolute } from '../utils/toAbsolute'
+import { toAbsolute, toAbsoluteUrl } from '../utils/toAbsolute'
 import { replaceLoader } from '../vite/replaceLoader'
 import type { One, RouteInfo } from '../vite/types'
 
@@ -174,7 +174,7 @@ prefetchCSS()
     recordTiming('writeCSSPreload', performance.now() - t0)
 
     t0 = performance.now()
-    const exported = await import(toAbsolute(serverJsPath))
+    const exported = await import(toAbsoluteUrl(serverJsPath))
     recordTiming('importServerModule', performance.now() - t0)
 
     const loaderProps: LoaderProps = { path, params }
@@ -195,7 +195,7 @@ prefetchCSS()
             // derive server dir from clientDir (e.g. dist/client -> dist/server)
             const serverDir = join(clientDir, '..', 'server')
             const layoutExported = await import(
-              toAbsolute(join(serverDir, layoutServerPath))
+              toAbsoluteUrl(join(serverDir, layoutServerPath))
             )
             const layoutLoaderData = await layoutExported?.loader?.(loaderProps)
             return { contextKey: layout.contextKey, loaderData: layoutLoaderData }
@@ -478,7 +478,7 @@ params:\n\n${JSON.stringify(params || null, null, 2)}`
 
 async function getRender(serverEntry: string) {
   try {
-    const serverImport = await import(serverEntry)
+    const serverImport = await import(toAbsoluteUrl(serverEntry))
 
     const render =
       serverImport.default.render ||
diff --git a/packages/one/src/metro-config/getViteMetroPluginOptions.test.ts b/packages/one/src/metro-config/getViteMetroPluginOptions.test.ts
new file mode 100644
index 0000000000..d96918a5ac
--- /dev/null
+++ b/packages/one/src/metro-config/getViteMetroPluginOptions.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, it } from 'vitest'
+import { normalizeReSource } from './getViteMetroPluginOptions'
+
+// String.raw avoids double-escaping: String.raw`[\\/]` is the 5-char string [ \ \ / ]
+// which is exactly what regex.source produces for /[\\/]/
+
+describe('normalizeReSource', () => {
+  it(String.raw`[\\/] to \/`, () => {
+    expect(normalizeReSource(String.raw`[\\/]`)).toBe(String.raw`\/`)
+  })
+
+  it(String.raw`[^\\/] to [^/]`, () => {
+    expect(normalizeReSource(String.raw`[^\\/]`)).toBe('[^/]')
+  })
+
+  it('full Windows micromatch regex', () => {
+    // micromatch.makeRe('**/*.web.(ts|tsx)').source on Windows (picomatch 2.x)
+    const windowsSource = String.raw`^(?:(?:^|[\\/]|(?:(?:(?!(?:^|[\\/])\.).)*?)[\\/])(?!\.)(?=.)[^\\/]*?\.web\.(ts|tsx))$`
+    const posixSource = String.raw`^(?:(?:^|\/|(?:(?:(?!(?:^|\/)\.).)*?)\/)(?!\.)(?=.)[^/]*?\.web\.(ts|tsx))$`
+
+    expect(normalizeReSource(windowsSource)).toBe(posixSource)
+  })
+
+  it('no-op for POSIX regex', () => {
+    const posixSource = String.raw`^(?:(?:^|\/|(?:(?:(?!(?:^|\/)\.).)*?)\/)(?!\.)(?=.)[^/]*?\.web\.(ts|tsx))$`
+
+    expect(normalizeReSource(posixSource)).toBe(posixSource)
+  })
+
+  it('multiple groups in one source', () => {
+    const source = String.raw`a[\\/]b[\\/]c[^\\/]d`
+    expect(normalizeReSource(source)).toBe(String.raw`a\/b\/c[^/]d`)
+  })
+})
diff --git a/packages/one/src/metro-config/getViteMetroPluginOptions.ts b/packages/one/src/metro-config/getViteMetroPluginOptions.ts
index 1117039a5c..173b9f92d9 100644
--- a/packages/one/src/metro-config/getViteMetroPluginOptions.ts
+++ b/packages/one/src/metro-config/getViteMetroPluginOptions.ts
@@ -8,6 +8,14 @@ import {
   ROUTE_NATIVE_EXCLUSION_GLOB_PATTERNS,
 } from '../router/glob-patterns'
 
+/**
+ * On Windows, micromatch.makeRe() produces regex patterns with `[\\/]` or `[^\\/]`
+ * instead of `\/` and `[^/]`. Normalize them so the startsWith check works.
+ */
+export function normalizeReSource(source: string): string {
+  return source.replace(/\[\\\\\/\]/g, '\\/').replace(/\[\^\\\\\/\]/g, '[^/]')
+}
+
 export function getViteMetroPluginOptions({
   projectRoot,
   relativeRouterRoot,
@@ -56,7 +64,7 @@ export function getViteMetroPluginOptions({
        * ^(?:(?:^|\/|(?:(?:(?!(?:^|\/)\.).)*?)\/)(?!\.)(?=.)[^/]*?\+api\.(ts|tsx))$
        * ```
        */
-      const reSource = re.source
+      const reSource = normalizeReSource(re.source)
 
       if (
         !(
@@ -112,13 +120,7 @@ export function getViteMetroPluginOptions({
             //     .filter((i): i is NonNullable<typeof i> => !!i)
             // ),
           },
-          nodeModulesPaths: tsconfigPathsConfigLoadResult.absoluteBaseUrl
-            ? [
-                // "vite-tsconfig-paths" for Metro
-                tsconfigPathsConfigLoadResult.absoluteBaseUrl,
-                ...(defaultConfig?.resolver?.nodeModulesPaths || []),
-              ]
-            : defaultConfig?.resolver?.nodeModulesPaths,
+          nodeModulesPaths: defaultConfig?.resolver?.nodeModulesPaths,
           resolveRequest: (context, moduleName, platform) => {
             if (moduleName.endsWith('.css')) {
               return {
@@ -153,12 +155,13 @@ export function getViteMetroPluginOptions({
               const defaultResolveRequest =
                 defaultConfig?.resolver?.resolveRequest || context.resolveRequest
               const res = defaultResolveRequest(context, moduleName, platform)
-              if (res && 'filePath' in res && res.filePath.includes('/src/index.ts')) {
+              const svgSrcSuffix = `${path.sep}src${path.sep}index.ts`
+              if (res && 'filePath' in res && res.filePath.includes(svgSrcSuffix)) {
                 return {
                   ...res,
                   filePath: res.filePath.replace(
-                    '/src/index.ts',
-                    '/lib/commonjs/index.js'
+                    svgSrcSuffix,
+                    `${path.sep}lib${path.sep}commonjs${path.sep}index.js`
                   ),
                 }
               }
diff --git a/packages/one/src/server/oneServe.ts b/packages/one/src/server/oneServe.ts
index d65bb7fc08..0739863b40 100644
--- a/packages/one/src/server/oneServe.ts
+++ b/packages/one/src/server/oneServe.ts
@@ -1,7 +1,7 @@
 import type { Hono, MiddlewareHandler } from 'hono'
 import type { BlankEnv } from 'hono/types'
 import { readFile } from 'node:fs/promises'
-import { join, resolve } from 'node:path'
+import { join } from 'node:path'
 import {
   CSS_PRELOAD_JS_POSTFIX,
   LOADER_JS_POSTFIX_UNCACHED,
@@ -16,7 +16,7 @@ import {
 } from '../createHandleRequest'
 import type { RenderAppProps } from '../types'
 import { getPathFromLoaderPath } from '../utils/cleanUrl'
-import { toAbsolute } from '../utils/toAbsolute'
+import { toAbsoluteUrl } from '../utils/toAbsolute'
 import type { One } from '../vite/types'
 import type { RouteInfoCompiled } from './createRoutesManifest'
 import { setSSRLoaderData } from './ssrLoaderData'
@@ -160,8 +160,8 @@ export async function oneServe(
         routeExported = lazyKey
           ? options?.lazyRoutes?.pages?.[lazyKey]
             ? await options.lazyRoutes.pages[lazyKey]()
-            : await import(toAbsolute(resolvedPath))
-          : await import(toAbsolute(serverPath!))
+            : await import(toAbsoluteUrl(resolvedPath))
+          : await import(toAbsoluteUrl(serverPath!))
         moduleImportCache.set(cacheKey, routeExported)
       }
 
@@ -264,8 +264,7 @@ export async function oneServe(
       const entry = options?.lazyRoutes?.serverEntry
         ? await options.lazyRoutes.serverEntry()
         : await import(
-            resolve(
-              process.cwd(),
+            toAbsoluteUrl(
               `${serverOptions.root}/${outDir}/server/_virtual_one-entry.${typeof oneOptions.build?.server === 'object' && oneOptions.build.server.outputFormat === 'cjs' ? 'c' : ''}js`
             )
           )
@@ -300,13 +299,8 @@ export async function oneServe(
       }
       // both vite and rolldown-vite replace brackets with underscores in output filenames
       const fileName = route.page.slice(1).replace(/\[/g, '_').replace(/\]/g, '_')
-      const apiFile = join(
-        process.cwd(),
-        outDir,
-        'api',
-        fileName + (apiCJS ? '.cjs' : '.js')
-      )
-      return await import(apiFile)
+      const apiFile = join(outDir, 'api', fileName + (apiCJS ? '.cjs' : '.js'))
+      return await import(toAbsoluteUrl(apiFile))
     },
 
     async loadMiddleware(route) {
@@ -314,7 +308,7 @@ export async function oneServe(
       if (options?.lazyRoutes?.middlewares?.[route.contextKey]) {
         return await options.lazyRoutes.middlewares[route.contextKey]()
       }
-      return await import(toAbsolute(route.contextKey))
+      return await import(toAbsoluteUrl(route.contextKey))
     },
 
     async handleLoader({ route, loaderProps }) {
diff --git a/packages/one/src/utils/toAbsolute.ts b/packages/one/src/utils/toAbsolute.ts
index 6bfb52ee17..a8e754e0ae 100644
--- a/packages/one/src/utils/toAbsolute.ts
+++ b/packages/one/src/utils/toAbsolute.ts
@@ -1,3 +1,8 @@
 import { resolve } from 'node:path'
+import { pathToFileURL } from 'node:url'
 
+/** Resolve to native filesystem path — for fs operations (readFile, writeFile, join). */
 export const toAbsolute = (p: string) => resolve(process.cwd(), p)
+
+/** Resolve to file:// URL — for dynamic import() which requires URLs on Windows. */
+export const toAbsoluteUrl = (p: string) => pathToFileURL(resolve(process.cwd(), p)).href
diff --git a/packages/one/src/utils/workerImport.ts b/packages/one/src/utils/workerImport.ts
index 0bde559c32..bfdf319183 100644
--- a/packages/one/src/utils/workerImport.ts
+++ b/packages/one/src/utils/workerImport.ts
@@ -4,7 +4,7 @@
  *
  * Usage: Pass the caller's import.meta.url to resolve relative paths correctly.
  */
-import { fileURLToPath } from 'node:url'
+import { fileURLToPath, pathToFileURL } from 'node:url'
 import { dirname, resolve } from 'node:path'
 
 type ModuleCache = Map<string, any>
@@ -33,7 +33,7 @@ export async function workerImport<T = any>(
   const mjsPath = absolutePath.endsWith('.mjs') ? absolutePath : `${absolutePath}.mjs`
 
   // @ts-ignore - runtime needs .mjs extension for proper ESM resolution
-  const mod = await import(mjsPath)
+  const mod = await import(pathToFileURL(mjsPath).href)
   cache.set(cacheKey, mod)
   return mod
 }
diff --git a/packages/one/src/vite/plugins/criticalCSSPlugin.test.ts b/packages/one/src/vite/plugins/criticalCSSPlugin.test.ts
index 8ebc7bf624..6408e03702 100644
--- a/packages/one/src/vite/plugins/criticalCSSPlugin.test.ts
+++ b/packages/one/src/vite/plugins/criticalCSSPlugin.test.ts
@@ -1,5 +1,8 @@
+import { resolve } from 'node:path'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
+const PROJECT_ROOT = resolve('/project')
+
 describe('criticalCSSPlugin', () => {
   beforeEach(() => {
     vi.resetModules()
@@ -14,12 +17,12 @@ describe('criticalCSSPlugin', () => {
       const { criticalCSSPlugin } = await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
       const result = await (plugin.resolveId as any).call(
         { resolve: vi.fn() },
         './styles.css',
-        '/project/src/App.tsx'
+        resolve('/project/src/App.tsx')
       )
       expect(result).toBeNull()
     })
@@ -28,12 +31,12 @@ describe('criticalCSSPlugin', () => {
       const { criticalCSSPlugin } = await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
       const result = await (plugin.resolveId as any).call(
         { resolve: vi.fn() },
         './data.json',
-        '/project/src/App.tsx'
+        resolve('/project/src/App.tsx')
       )
       expect(result).toBeNull()
     })
@@ -42,25 +45,25 @@ describe('criticalCSSPlugin', () => {
       const { criticalCSSPlugin } = await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
+      const resolvedCssPath = resolve('/project/src/styles.inline.css')
       const mockResolve = vi.fn().mockResolvedValue({
-        id: '/project/src/styles.inline.css',
+        id: resolvedCssPath,
       })
 
+      const importerPath = resolve('/project/src/App.tsx')
       const result = await (plugin.resolveId as any).call(
         { resolve: mockResolve },
         './styles.inline.css',
-        '/project/src/App.tsx'
+        importerPath
       )
 
-      expect(mockResolve).toHaveBeenCalledWith(
-        './styles.inline.css',
-        '/project/src/App.tsx',
-        { skipSelf: true }
-      )
+      expect(mockResolve).toHaveBeenCalledWith('./styles.inline.css', importerPath, {
+        skipSelf: true,
+      })
 
-      expect(result).toEqual({ id: '/project/src/styles.inline.css' })
+      expect(result).toEqual({ id: resolvedCssPath })
     })
 
     it('should track inline CSS source paths', async () => {
@@ -68,34 +71,37 @@ describe('criticalCSSPlugin', () => {
         await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
       const mockResolve = vi.fn().mockResolvedValue({
-        id: '/project/src/layout.inline.css',
+        id: resolve('/project/src/layout.inline.css'),
       })
 
       await (plugin.resolveId as any).call(
         { resolve: mockResolve },
         './layout.inline.css',
-        '/project/src/App.tsx'
+        resolve('/project/src/App.tsx')
       )
 
       const sources = getCriticalCSSSources()
-      expect(sources.has('src/layout.inline.css')).toBe(true)
+      // relative() produces forward slashes on POSIX, backslashes on Windows
+      expect(
+        sources.has('src/layout.inline.css') || sources.has('src\\layout.inline.css')
+      ).toBe(true)
     })
 
     it('should return null when resolve fails', async () => {
       const { criticalCSSPlugin } = await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
       const mockResolve = vi.fn().mockResolvedValue(null)
 
       const result = await (plugin.resolveId as any).call(
         { resolve: mockResolve },
         './nonexistent.inline.css',
-        '/project/src/App.tsx'
+        resolve('/project/src/App.tsx')
       )
 
       expect(result).toBeNull()
@@ -108,21 +114,25 @@ describe('criticalCSSPlugin', () => {
         await import('./criticalCSSPlugin')
       const plugin = criticalCSSPlugin()
 
-      ;(plugin.configResolved as any)({ root: '/project' })
+      ;(plugin.configResolved as any)({ root: PROJECT_ROOT })
 
       const mockResolve = vi.fn().mockResolvedValue({
-        id: '/project/app/layout.inline.css',
+        id: resolve('/project/app/layout.inline.css'),
       })
       await (plugin.resolveId as any).call(
         { resolve: mockResolve },
         './layout.inline.css',
-        '/project/app/_layout.tsx'
+        resolve('/project/app/_layout.tsx')
       )
 
+      // Build a manifest keyed by the relative path that criticalCSSSources actually stores
+      const sources = getCriticalCSSSources()
+      const sourceKey = [...sources].find((s) => s.includes('layout.inline.css'))!
+
       const manifest = {
-        'app/layout.inline.css': {
+        [sourceKey]: {
           file: 'assets/layout-abc123.css',
-          src: 'app/layout.inline.css',
+          src: sourceKey,
         },
         'app/_layout.tsx': {
           file: 'assets/layout-def456.js',
diff --git a/packages/one/src/vite/plugins/criticalCSSPlugin.ts b/packages/one/src/vite/plugins/criticalCSSPlugin.ts
index 0427ac4054..d935cb6152 100644
--- a/packages/one/src/vite/plugins/criticalCSSPlugin.ts
+++ b/packages/one/src/vite/plugins/criticalCSSPlugin.ts
@@ -1,4 +1,5 @@
 import { relative } from 'node:path'
+import { normalizePath } from 'vite'
 import type { Plugin } from 'vite'
 
 /**
@@ -62,8 +63,8 @@ export function criticalCSSPlugin(): Plugin {
       const resolved = await this.resolve(id, importer, { skipSelf: true })
 
       if (resolved) {
-        // store as relative path to match manifest keys
-        const relativePath = relative(root, resolved.id)
+        // store as relative path to match manifest keys (forward slashes to match Vite)
+        const relativePath = normalizePath(relative(root, resolved.id))
         criticalCSSSources.add(relativePath)
         return resolved
       }
diff --git a/packages/one/src/vite/plugins/imageDataPlugin.test.ts b/packages/one/src/vite/plugins/imageDataPlugin.test.ts
index 5bcb662333..f7669bb93a 100644
--- a/packages/one/src/vite/plugins/imageDataPlugin.test.ts
+++ b/packages/one/src/vite/plugins/imageDataPlugin.test.ts
@@ -1,5 +1,12 @@
+import { resolve } from 'node:path'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
+// Platform-correct test paths — resolve() normalizes to native separators
+const PROJECT_ROOT = resolve('/project')
+const PUBLIC_DIR = resolve('/project/public')
+const COMPONENTS_DIR = resolve('/project/src/components')
+const HERO_FILE = resolve('/project/src/components/Hero.tsx')
+
 // Mock fs before importing the plugin
 vi.mock('node:fs', async () => {
   const actual = await vi.importActual('node:fs')
@@ -11,6 +18,13 @@ vi.mock('node:fs', async () => {
   }
 })
 
+function mockConfig() {
+  return {
+    publicDir: PUBLIC_DIR,
+    root: PROJECT_ROOT,
+  }
+}
+
 describe('imageDataPlugin', () => {
   beforeEach(() => {
     vi.resetModules()
@@ -25,13 +39,8 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)('./image.jpg', undefined)
@@ -42,13 +51,8 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       // ?imagedata in the middle should not match
@@ -60,53 +64,38 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
         '/test-image.jpg?imagedata',
         undefined
       )
-      expect(result).toBe('\0imagedata:/project/public/test-image.jpg')
+      expect(result).toBe('\0imagedata:' + resolve(PUBLIC_DIR, 'test-image.jpg'))
     })
 
     it('should resolve relative imports', async () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
         './test-image.jpg?imagedata',
-        '/project/src/components/Hero.tsx'
+        HERO_FILE
       )
-      expect(result).toBe('\0imagedata:/project/src/components/test-image.jpg')
+      expect(result).toBe('\0imagedata:' + resolve(COMPONENTS_DIR, 'test-image.jpg'))
     })
 
     it('should return null for non-existent files', async () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
@@ -122,13 +111,8 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
@@ -142,18 +126,13 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
         '../../../../etc/passwd?imagedata',
-        '/project/src/components/Hero.tsx'
+        HERO_FILE
       )
       expect(result).toBeNull()
     })
@@ -162,13 +141,8 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const result = await (plugin.resolveId as any)(
@@ -182,22 +156,17 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       // Going up and back down should still work if within bounds
       // From /project/src/components, ../.. goes to /project, then src/test-image.jpg
       const result = await (plugin.resolveId as any)(
         '../../src/test-image.jpg?imagedata',
-        '/project/src/components/Hero.tsx'
+        HERO_FILE
       )
-      expect(result).toBe('\0imagedata:/project/src/test-image.jpg')
+      expect(result).toBe('\0imagedata:' + resolve(PROJECT_ROOT, 'src/test-image.jpg'))
     })
   })
 
@@ -206,13 +175,8 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const mockContext = {
@@ -227,33 +191,28 @@ describe('imageDataPlugin', () => {
       const { imageDataPlugin } = await import('./imageDataPlugin')
       const plugin = imageDataPlugin()
 
-      const mockConfig = {
-        publicDir: '/project/public',
-        root: '/project',
-      }
-
       if (plugin.configResolved) {
-        ;(plugin.configResolved as any)(mockConfig)
+        ;(plugin.configResolved as any)(mockConfig())
       }
 
       const mockContext = {
         addWatchFile: vi.fn(),
       }
 
+      const testFilePath = resolve(PUBLIC_DIR, 'test-image.jpg')
+
       // This will fail because the file doesn't actually exist
       // But it should gracefully fallback
       const result = await (plugin.load as any).call(
         mockContext,
-        '\0imagedata:/project/public/test-image.jpg'
+        '\0imagedata:' + testFilePath
       )
 
       expect(result).toContain('export default')
       expect(result).toContain('"src":"/test-image.jpg"')
       expect(result).toContain('"width":')
       expect(result).toContain('"height":')
-      expect(mockContext.addWatchFile).toHaveBeenCalledWith(
-        '/project/public/test-image.jpg'
-      )
+      expect(mockContext.addWatchFile).toHaveBeenCalledWith(testFilePath)
     })
   })
 
@@ -279,22 +238,19 @@ describe('imageDataPlugin output format', () => {
     const { imageDataPlugin } = await import('./imageDataPlugin')
     const plugin = imageDataPlugin()
 
-    const mockConfig = {
-      publicDir: '/project/public',
-      root: '/project',
-    }
-
     if (plugin.configResolved) {
-      ;(plugin.configResolved as any)(mockConfig)
+      ;(plugin.configResolved as any)(mockConfig())
     }
 
     const mockContext = {
       addWatchFile: vi.fn(),
     }
 
+    const testFilePath = resolve(PUBLIC_DIR, 'test-image.jpg')
+
     const result = await (plugin.load as any).call(
       mockContext,
-      '\0imagedata:/project/public/test-image.jpg'
+      '\0imagedata:' + testFilePath
     )
 
     // Extract JSON from the export
diff --git a/packages/one/src/vite/plugins/imageDataPlugin.ts b/packages/one/src/vite/plugins/imageDataPlugin.ts
index 5241748a45..82ce2a9d85 100644
--- a/packages/one/src/vite/plugins/imageDataPlugin.ts
+++ b/packages/one/src/vite/plugins/imageDataPlugin.ts
@@ -1,6 +1,7 @@
 import { existsSync } from 'node:fs'
-import { dirname, relative, resolve } from 'node:path'
+import { dirname, relative, resolve, sep } from 'node:path'
 import type { Plugin, ResolvedConfig } from 'vite'
+import { normalizePath } from 'vite'
 import { processImageMeta } from '../../image/getImageData'
 
 const IMAGEDATA_SUFFIX = '?imagedata'
@@ -12,14 +13,14 @@ export function imageDataPlugin(): Plugin {
 
   function getSrcPath(filePath: string): string {
     return filePath.startsWith(publicDir)
-      ? '/' + relative(publicDir, filePath)
-      : '/' + relative(root, filePath)
+      ? '/' + normalizePath(relative(publicDir, filePath))
+      : '/' + normalizePath(relative(root, filePath))
   }
 
   function isPathWithinBounds(filePath: string, allowedDir: string): boolean {
     const resolved = resolve(filePath)
     const allowed = resolve(allowedDir)
-    return resolved.startsWith(allowed + '/') || resolved === allowed
+    return resolved.startsWith(allowed + sep) || resolved === allowed
   }
 
   function createImageDataExport(src: string, width = 0, height = 0, blurDataURL = '') {
diff --git a/packages/one/types/metro-config/getViteMetroPluginOptions.d.ts b/packages/one/types/metro-config/getViteMetroPluginOptions.d.ts
index 8049d42cac..ac21ec19f3 100644
--- a/packages/one/types/metro-config/getViteMetroPluginOptions.d.ts
+++ b/packages/one/types/metro-config/getViteMetroPluginOptions.d.ts
@@ -1,4 +1,9 @@
 import type { metroPlugin } from '@vxrn/vite-plugin-metro';
+/**
+ * On Windows, micromatch.makeRe() produces regex patterns with `[\\/]` or `[^\\/]`
+ * instead of `\/` and `[^/]`. Normalize them so the startsWith check works.
+ */
+export declare function normalizeReSource(source: string): string;
 export declare function getViteMetroPluginOptions({ projectRoot, relativeRouterRoot, ignoredRouteFiles, userDefaultConfigOverrides, setupFile, }: {
     projectRoot: string;
     relativeRouterRoot: string;
diff --git a/packages/one/types/metro-config/getViteMetroPluginOptions.test.d.ts b/packages/one/types/metro-config/getViteMetroPluginOptions.test.d.ts
new file mode 100644
index 0000000000..85fb2c96b2
--- /dev/null
+++ b/packages/one/types/metro-config/getViteMetroPluginOptions.test.d.ts
@@ -0,0 +1,2 @@
+export {};
+//# sourceMappingURL=getViteMetroPluginOptions.test.d.ts.map
\ No newline at end of file
diff --git a/packages/one/types/utils/toAbsolute.d.ts b/packages/one/types/utils/toAbsolute.d.ts
index 2abcbbf84e..889cf041f8 100644
--- a/packages/one/types/utils/toAbsolute.d.ts
+++ b/packages/one/types/utils/toAbsolute.d.ts
@@ -1,2 +1,5 @@
+/** Resolve to native filesystem path — for fs operations (readFile, writeFile, join). */
 export declare const toAbsolute: (p: string) => string;
+/** Resolve to file:// URL — for dynamic import() which requires URLs on Windows. */
+export declare const toAbsoluteUrl: (p: string) => string;
 //# sourceMappingURL=toAbsolute.d.ts.map
\ No newline at end of file
diff --git a/packages/resolve/src/index.tsx b/packages/resolve/src/index.tsx
index e3a01d29d1..8ea28b659d 100644
--- a/packages/resolve/src/index.tsx
+++ b/packages/resolve/src/index.tsx
@@ -1,13 +1,24 @@
 import module from 'node:module'
-import { dirname, join } from 'node:path'
+import { dirname, join, resolve } from 'node:path'
 import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
 
 /**
  * Resolves a module path from the specified directory.
  * For npm packages, returns the ESM entry point when available.
  */
 export const resolvePath = (path: string, from = process.cwd()): string => {
-  const require = module.createRequire(from.endsWith('/') ? from : from + '/')
+  if (process.platform === 'win32' && from.startsWith('/')) {
+    try {
+      from = fileURLToPath('file://' + from)
+    } catch {
+      from = from.slice(1)
+    }
+  }
+  from = resolve(from)
+  const require = module.createRequire(
+    from.endsWith('/') || from.endsWith('\\') ? from : from + '/'
+  )
   const resolved = require.resolve(path, { paths: [from] })
 
   // For relative paths or node: builtins, just return the resolved path
diff --git a/packages/vite-plugin-metro/src/metro-config/getMetroConfigFromViteConfig.ts b/packages/vite-plugin-metro/src/metro-config/getMetroConfigFromViteConfig.ts
index 0f0754d13c..2d91ac7f7f 100644
--- a/packages/vite-plugin-metro/src/metro-config/getMetroConfigFromViteConfig.ts
+++ b/packages/vite-plugin-metro/src/metro-config/getMetroConfigFromViteConfig.ts
@@ -1,4 +1,5 @@
 import type { ResolvedConfig } from 'vite'
+import { resolve } from 'node:path'
 import micromatch from 'micromatch'
 
 // For Metro and Expo, we only import types here.
@@ -23,7 +24,7 @@ export async function getMetroConfigFromViteConfig(
   // prefer argv.projectRoot (user override) over config.root (vite resolved)
   // this is needed for monorepo setups where config.root may resolve to
   // the monorepo root instead of the app subdirectory
-  const projectRoot = metroPluginOptions.argv?.projectRoot ?? config.root
+  const projectRoot = resolve(metroPluginOptions.argv?.projectRoot ?? config.root)
   const { mainModuleName, argv, defaultConfigOverrides, watchman, excludeModules } =
     metroPluginOptions
 
diff --git a/packages/vite-plugin-metro/src/plugins/metroPlugin.ts b/packages/vite-plugin-metro/src/plugins/metroPlugin.ts
index 0a36972aee..072f7c62a4 100644
--- a/packages/vite-plugin-metro/src/plugins/metroPlugin.ts
+++ b/packages/vite-plugin-metro/src/plugins/metroPlugin.ts
@@ -1,5 +1,6 @@
 import { existsSync } from 'node:fs'
 import { readFile } from 'node:fs/promises'
+import { resolve } from 'node:path'
 import type { PluginOption } from 'vite'
 import launchEditor from 'launch-editor'
 import { createDebugger } from '@vxrn/debug'
@@ -84,7 +85,7 @@ export function metroPlugin(options: MetroPluginOptions = {}): PluginOption {
     // },
 
     configureServer(server) {
-      const { root: projectRoot } = server.config
+      const projectRoot = resolve(server.config.root)
 
       let metroReady = false
 
diff --git a/packages/vite-plugin-metro/src/utils/projectImport.ts b/packages/vite-plugin-metro/src/utils/projectImport.ts
index e09a4b7a2a..f0cd8573a1 100644
--- a/packages/vite-plugin-metro/src/utils/projectImport.ts
+++ b/packages/vite-plugin-metro/src/utils/projectImport.ts
@@ -1,5 +1,6 @@
 import { createDebugger } from '@vxrn/debug'
 import module from 'node:module'
+import { pathToFileURL } from 'node:url'
 
 export const { debug } = createDebugger('vite-metro:projectImport')
 
@@ -18,7 +19,7 @@ export async function projectImport<T = any>(
 
     debug?.(`Importing "${path}" from project root: "${projectRoot}" at "${importPath}"`)
 
-    const out = await import(importPath)
+    const out = await import(pathToFileURL(importPath).href)
 
     // somewhat hacky fix but for some reason in new takeout repo its double-wrapping default export
     if (out?.default?.default) {
diff --git a/packages/vxrn/src/config/getBaseViteConfigOnly.ts b/packages/vxrn/src/config/getBaseViteConfigOnly.ts
index f3422c067c..b6b526807c 100644
--- a/packages/vxrn/src/config/getBaseViteConfigOnly.ts
+++ b/packages/vxrn/src/config/getBaseViteConfigOnly.ts
@@ -98,10 +98,7 @@ export async function getBaseViteConfig(
         // have these native-only subpaths
         {
           find: /^react-native\/Libraries\/.*/,
-          replacement: resolvePath(
-            '@vxrn/vite-plugin-metro/empty',
-            new URL('.', import.meta.url).pathname
-          ),
+          replacement: resolvePath('@vxrn/vite-plugin-metro/empty', import.meta.dirname),
         },
         {
           find: 'react-native/package.json',
diff --git a/packages/vxrn/src/exports/prebuild.ts b/packages/vxrn/src/exports/prebuild.ts
index 7466204096..ed977d73fa 100644
--- a/packages/vxrn/src/exports/prebuild.ts
+++ b/packages/vxrn/src/exports/prebuild.ts
@@ -2,6 +2,7 @@ import { resolvePath } from '@vxrn/resolve'
 import { detectPackageManager, type PackageManagerName } from '@vxrn/utils'
 import FSExtra from 'fs-extra'
 import path from 'node:path'
+import { pathToFileURL } from 'node:url'
 import colors from 'picocolors'
 import { fillOptions } from '../config/getOptionsFilled'
 import { applyBuiltInPatches } from '../utils/patches'
@@ -29,7 +30,8 @@ export const prebuild = async ({
     try {
       // Import Expo from the user's project instead of from where vxrn is installed, since vxrn may be installed globally or at the root workspace.
       const importPath = resolvePath('@expo/cli/build/src/prebuild/index.js', root)
-      const expoPrebuild = (await import(importPath)).default.expoPrebuild
+      const expoPrebuild = (await import(pathToFileURL(importPath).href)).default
+        .expoPrebuild
       await expoPrebuild([
         ...(platform ? ['--platform', platform] : []),
         ...(noInstall ? ['--no-install'] : []),
diff --git a/packages/vxrn/src/exports/prebuildWithoutExpo.ts b/packages/vxrn/src/exports/prebuildWithoutExpo.ts
index 96400619dd..d74866b15b 100644
--- a/packages/vxrn/src/exports/prebuildWithoutExpo.ts
+++ b/packages/vxrn/src/exports/prebuildWithoutExpo.ts
@@ -1,5 +1,6 @@
 import module from 'node:module'
 import path from 'node:path'
+import { pathToFileURL } from 'node:url'
 import FSExtra from 'fs-extra'
 
 /*
@@ -27,7 +28,7 @@ export const generateForPlatform = async (
     ),
     platform
   )
-  const walk = (await import(importPath)).default.default
+  const walk = (await import(pathToFileURL(importPath).href)).default.default
   walk(src).forEach((absoluteSrc: string) => {
     const relativeFilePath = transformPath(path.relative(src, absoluteSrc))
       .replace(/HelloWorld/g, appName)
diff --git a/packages/vxrn/src/plugins/expoManifestRequestHandlerPlugin.ts b/packages/vxrn/src/plugins/expoManifestRequestHandlerPlugin.ts
index 5166a314bc..d0bd53f9a2 100644
--- a/packages/vxrn/src/plugins/expoManifestRequestHandlerPlugin.ts
+++ b/packages/vxrn/src/plugins/expoManifestRequestHandlerPlugin.ts
@@ -1,6 +1,7 @@
 import { join } from 'node:path'
 import module from 'node:module'
 import { TLSSocket } from 'node:tls'
+import { pathToFileURL } from 'node:url'
 
 import type { Plugin } from 'vite'
 import colors from 'picocolors'
@@ -48,8 +49,8 @@ export function expoManifestRequestHandlerPlugin(
             '@expo/cli/build/src/start/server/middleware/ExpoGoManifestHandlerMiddleware.js',
             { paths: [projectRoot] }
           )
-          ExpoGoManifestHandlerMiddleware = (await import(importPath)).default
-            .ExpoGoManifestHandlerMiddleware
+          ExpoGoManifestHandlerMiddleware = (await import(pathToFileURL(importPath).href))
+            .default.ExpoGoManifestHandlerMiddleware
         } catch (e) {
           expoGoManifestHandlerMiddlewareImportError = e
         }
diff --git a/packages/vxrn/src/user-interface/index.ts b/packages/vxrn/src/user-interface/index.ts
index d6823401bf..a946522dfc 100644
--- a/packages/vxrn/src/user-interface/index.ts
+++ b/packages/vxrn/src/user-interface/index.ts
@@ -1,5 +1,6 @@
 import { exec } from 'node:child_process'
 import module from 'node:module'
+import { pathToFileURL } from 'node:url'
 import type { ViteDevServer } from 'vite'
 import { filterViteServerResolvedUrls } from '../utils/filterViteServerResolvedUrls'
 
@@ -313,7 +314,9 @@ async function openIos(ctx: Context) {
         paths: [projectRoot],
       }
     )
-    const applePlatformManagerModule = await import(applePlatformManagerModuleImportPath)
+    const applePlatformManagerModule = await import(
+      pathToFileURL(applePlatformManagerModuleImportPath).href
+    )
     const PlatformManager = applePlatformManagerModule.default.ApplePlatformManager
 
     // TODO: Support dev client
@@ -347,7 +350,7 @@ async function openAndroid(ctx: Context) {
       }
     )
     const androidPlatformManagerModule = await import(
-      androidPlatformManagerModuleImportPath
+      pathToFileURL(androidPlatformManagerModuleImportPath).href
     )
     const PlatformManager = androidPlatformManagerModule.default.AndroidPlatformManager
 
diff --git a/packages/vxrn/src/utils/createNativeDevEngine.ts b/packages/vxrn/src/utils/createNativeDevEngine.ts
index caaae2d517..9f9bd3b04a 100644
--- a/packages/vxrn/src/utils/createNativeDevEngine.ts
+++ b/packages/vxrn/src/utils/createNativeDevEngine.ts
@@ -828,7 +828,8 @@ function assetPlugin(opts: { root: string; platform: string }): Plugin {
         const name = basename(id, `.${ext}`)
         const dir = dirname(id)
         const relativePath = relative(opts.root, id)
-        const httpLocation = '/assets/' + dirname(relativePath)
+        // On Windows, change backslashes to slashes to get proper URL path from file path.
+        const httpLocation = '/assets/' + dirname(relativePath).replace(/\\/g, '/')
 
         // simple asset registration (TODO: scale detection like rollipop)
         const assetData = {
diff --git a/packages/vxrn/src/utils/expoRun.ts b/packages/vxrn/src/utils/expoRun.ts
index f997df7edf..452a0ba1d4 100644
--- a/packages/vxrn/src/utils/expoRun.ts
+++ b/packages/vxrn/src/utils/expoRun.ts
@@ -1,4 +1,5 @@
 import module from 'node:module'
+import { pathToFileURL } from 'node:url'
 import { fillOptions } from '../config/getOptionsFilled'
 import { applyBuiltInPatches } from '../utils/patches'
 
@@ -23,7 +24,7 @@ export async function expoRun({
     const importPath = require.resolve(`@expo/cli/build/src/run/${platform}/index.js`, {
       paths: [root],
     })
-    const expoRun = (await import(importPath)).default[
+    const expoRun = (await import(pathToFileURL(importPath).href)).default[
       `expoRun${platform.charAt(0).toUpperCase() + platform.slice(1)}`
     ]
     await expoRun([
diff --git a/packages/vxrn/src/utils/isWithin.ts b/packages/vxrn/src/utils/isWithin.ts
index 1279e0cbcd..47186faf59 100644
--- a/packages/vxrn/src/utils/isWithin.ts
+++ b/packages/vxrn/src/utils/isWithin.ts
@@ -1,6 +1,6 @@
-import { relative } from 'node:path'
+import { isAbsolute, relative } from 'node:path'
 
 export function isWithin(outer: string, inner: string) {
   const rel = relative(outer, inner)
-  return !rel.startsWith('../') && rel !== '..'
+  return !rel.startsWith('..') && !isAbsolute(rel)
 }