diff --git a/.changeset/windows-codegraph-launch.md b/.changeset/windows-codegraph-launch.md
new file mode 100644
index 0000000..2c7400d
--- /dev/null
+++ b/.changeset/windows-codegraph-launch.md
@@ -0,0 +1,5 @@
+---
+"@vndv/pi-codegraph": patch
+---
+
+Resolve the CodeGraph CLI through Windows-native command discovery before launching the MCP server on Windows, while preserving the existing direct `codegraph` spawn path on other platforms.
diff --git a/__tests__/codegraph.test.ts b/__tests__/codegraph.test.ts
index 9b010c7..fd3bd60 100644
--- a/__tests__/codegraph.test.ts
+++ b/__tests__/codegraph.test.ts
@@ -3,6 +3,7 @@ import { EventEmitter } from "node:events";
 import { PassThrough } from "node:stream";
 import os from "node:os";
 import path from "node:path";
+import { fileURLToPath } from "node:url";
 
 vi.mock("node:child_process", () => ({
   spawn: vi.fn(() => createMockProcess()),
@@ -60,12 +61,60 @@ describe("pi-codegraph extension", () => {
     await expect(callCodeGraphTool("codegraph_status", {})).resolves.toBe("called codegraph_status");
   });
 
+  it("uses the direct codegraph executable outside Windows", async () => {
+    vi.spyOn(process, "platform", "get").mockReturnValue("linux");
+    const { spawn } = await import("node:child_process");
+    const { withCodeGraphMcp } = await import("../extensions/codegraph.js");
+
+    await withCodeGraphMcp(process.cwd(), undefined, async () => "success");
+
+    expect(spawn).toHaveBeenCalledWith("codegraph", ["serve", "--mcp", "--path", process.cwd()], {
+      cwd: process.cwd(),
+      env: process.env,
+      stdio: ["pipe", "pipe", "pipe"],
+    });
+  });
+
+  it("uses PowerShell command discovery for the CodeGraph executable on Windows", async () => {
+    vi.spyOn(process, "platform", "get").mockReturnValue("win32");
+    const { spawn } = await import("node:child_process");
+    const { withCodeGraphMcp } = await import("../extensions/codegraph.js");
+
+    await withCodeGraphMcp(process.cwd(), undefined, async () => "success");
+
+    const [command, args, options] = vi.mocked(spawn).mock.calls.at(-1)!;
+    const spawnArgs = args as string[];
+    const script = spawnArgs[spawnArgs.indexOf("-Command") + 1];
+
+    expect(command).toBe("powershell.exe");
+    expect(spawnArgs).toEqual(expect.arrayContaining([
+      "-NoProfile",
+      "-NonInteractive",
+      "-ExecutionPolicy",
+      "Bypass",
+      "-Command",
+    ]));
+    expect(script).toContain("Get-Command codegraph");
+    expect(script).toContain("-CommandType Application");
+    expect(script).toContain("Select-Object -First 1");
+    expect(script).not.toContain("codegraph.cmd");
+    expect(script).not.toMatch(/Users[\\/]cq/i);
+    expect(script).not.toMatch(/scoop/i);
+    expect(spawnArgs.at(-1)).toBe(process.cwd());
+    expect(options).toEqual({
+      cwd: process.cwd(),
+      env: process.env,
+      stdio: ["pipe", "pipe", "pipe"],
+      windowsHide: true,
+    });
+  });
+
   it("validates projectPath before starting CodeGraph", async () => {
     const { resolveProjectCwd } = await import("../extensions/codegraph.js");
 
     await expect(resolveProjectCwd("relative/project")).rejects.toThrow("absolute path");
     await expect(resolveProjectCwd("/path/that/does/not/exist")).rejects.toThrow("does not exist");
-    await expect(resolveProjectCwd(new URL(import.meta.url).pathname)).rejects.toThrow("directory");
+    await expect(resolveProjectCwd(fileURLToPath(import.meta.url))).rejects.toThrow("directory");
   });
 
   it("preserves Unix paths on macOS/Linux", async () => {
diff --git a/extensions/codegraph.ts b/extensions/codegraph.ts
index c988082..27b6c60 100644
--- a/extensions/codegraph.ts
+++ b/extensions/codegraph.ts
@@ -125,17 +125,52 @@ export const SessionTimeoutMs = 20_000;
 
 export const codegraphToolNames = ToolDefinitions.map((tool) => tool.name);
 
+const WindowsCodeGraphLaunchScript = [
+  "& {",
+  "param([string]$ProjectPath)",
+  "$ErrorActionPreference = 'Stop';",
+  "$cmd = Get-Command codegraph -CommandType Application -ErrorAction Stop | Select-Object -First 1;",
+  "if (-not $cmd) { throw 'codegraph command not found'; }",
+  "& $cmd.Source serve --mcp --path $ProjectPath;",
+  "exit $LASTEXITCODE;",
+  "}",
+].join(" ");
+
+function spawnCodeGraphServer(cwd: string): ChildProcessWithoutNullStreams {
+  if (process.platform !== "win32") {
+    return spawn("codegraph", ["serve", "--mcp", "--path", cwd], {
+      cwd,
+      env: process.env,
+      stdio: ["pipe", "pipe", "pipe"],
+    });
+  }
+
+  // On Windows, Node's direct spawn can miss npm/Scoop command shims that the
+  // shell resolves correctly. Use PowerShell command discovery so global CLI
+  // installs are found without hardcoding .cmd, Scoop, npm, or user paths.
+  return spawn("powershell.exe", [
+    "-NoProfile",
+    "-NonInteractive",
+    "-ExecutionPolicy",
+    "Bypass",
+    "-Command",
+    WindowsCodeGraphLaunchScript,
+    cwd,
+  ], {
+    cwd,
+    env: process.env,
+    stdio: ["pipe", "pipe", "pipe"],
+    windowsHide: true,
+  });
+}
+
 export async function withCodeGraphMcp<T>(
   projectPath: string | undefined,
   signal: AbortSignal | undefined,
   fn: (request: JsonRpcRequest) => Promise<T>,
 ): Promise<T> {
   const cwd = await resolveProjectCwd(projectPath);
-  const child = spawn("codegraph", ["serve", "--mcp", "--path", cwd], {
-    cwd,
-    env: process.env,
-    stdio: ["pipe", "pipe", "pipe"],
-  });
+  const child = spawnCodeGraphServer(cwd);
 
   const session = runJsonRpcSession(child, cwd, signal, fn);