NSIS Notepad4 Installer

An NSIS script that builds a Windows installer for the Notepad4 binaries (Notepad4 and matepath), with an option to replace Windows Notepad.

Status: maintained, bumped with each Notepad4 release. Download the installer from Releases.

Features

• Installs Notepad4 and matepath (default folder C:\Program Files\Notepad4; an update reuses the previous install's folder), with Start menu shortcuts and an Apps & Features entry
• Optional: Replace Windows Editor — every notepad.exe launch opens Notepad4 (Windows 10/11)
• Optional: Fetch latest version (online) — opt-in; queries GitHub for the latest Notepad4 release and installs it instead of the bundled one if its tag differs (see Online update). No internet access happens unless you select this option.
• Silent installation support

Bundled Version

The current installer bundles Notepad4 v26.10r6392 (English, x64).

Usage

Interactive Installation

Run the installer. By default only Notepad4 is selected and the bundled version is installed offline. The components page offers three install types:

Install type	Notepad4	Replace Windows Editor	Fetch latest version (online)
Minimal (preselected)	✓
Typical	✓	✓
Full	✓	✓	✓

Silent Installation

notepad4_en_x64_v26.10r6392-install.exe /S /I=full

• /S — Silent mode (no GUI)
• /I=full — also replace Windows Notepad (does not enable the online fetch)
• /I=minimal — Notepad4 only (the default; any value other than full behaves the same)
• /UPDATE — enable the online fetch of the latest version (silent mode only)
• /D=C:\path\to\Notepad4 — install folder; must be the last parameter and unquoted, even with spaces. Without it the previous install's folder is used, else C:\Program Files\Notepad4.

Replace Windows Editor

The section registers "<install folder>\Notepad4.exe" /z as the Debugger for notepad.exe under HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options. On Windows 11 it also removes the Windows Notepad app package (Get-AppxPackage *Microsoft.WindowsNotepad* | Remove-AppxPackage) and adds the IFEO filter entries.

Online update

The Fetch latest version (online) section (or /UPDATE in silent mode) extracts two PowerShell helpers to the installer's $PLUGINSDIR and runs them. Every file they read and write stays in that folder: it is new for each run, only administrators can write to it, and the installer deletes it when it exits. Nothing goes through the user-writable %TEMP%, so the files the installer copies are the ones whose zip passed the SHA-256 check.

1. check_update.ps1 asks the GitHub API for the latest zufuliu/notepad4 release (10 s timeout).
   • It picks the first asset matching Notepad4_en_x64_*.zip that is not an HD build.
   • It writes TagName, DownloadURL, SHA256 (the asset's digest from the API) and Status (OK, NoAsset or Error) to notepad4_update.ini.
2. If the status is OK and the tag differs from BUNDLED_VERSION, the installer asks whether to download it (silent mode downloads without asking).
3. download_update.ps1 downloads the zip (60 s timeout) to Notepad4_latest.zip.
   • It rejects (and deletes) the zip unless its SHA-256 equals SHA256; a missing digest is a rejection too.
   • It extracts the zip to Notepad4_latest (moving the contents of a top-level folder up) and copies every *.ini-default to *.ini.
   • It writes OK or FAIL to notepad4_download_status.txt.
4. On OK the installer copies the downloaded Notepad4.exe, matepath.exe, the three .ini files and License.txt over the bundled ones.
   • It records the new tag as the version in Apps & Features.
   • Otherwise it installs the bundled version (with a message in interactive mode).

Uninstallation

The uninstaller removes the Notepad4 files, Start menu shortcuts and registry entries. If Windows Notepad was replaced, it is restored (on Windows 11 the Windows Notepad app package is re-registered).

Building

Compile with NSIS 3 (Windows, or Linux with apt install nsis):

makensis -WX Notepad4_en_x64_v26.10r6392.nsi

This writes notepad4_en_x64_v26.10r6392-install.exe next to the script (git-ignored). The script includes psexec.nsh (PowerShell exec macros) and embeds the two update helpers and Notepad4_Installer.ico. CI (ci.yml) compiles it with warnings as errors on every push and pull request, and runs the E2E suite.

E2E

scripts/e2e.sh compiles the installer and a fixture build. In the fixture build the online fetch asks 127.0.0.1:${PORT_BASE:-8765} instead of the GitHub API. The script then runs these tests:

• the screenshot tour, as the sweep over every wizard page;
• e2e/test-install.ps1: /D= and the previous install folder;
• e2e/test-silent.ps1: what /S and /I= install, that notepad.exe opens Notepad4 after /I=full, the uninstaller, and quitting the wizard;
• e2e/test-update.ps1: the online fetch against a local fake of the release API, both silent and in the wizard (its two message boxes, and the component ticked by hand);
• e2e/test-download.ps1: the SHA-256 check of the download;
• e2e/test-wizard.ps1: a typed install folder and Start menu folder, "Do not create shortcuts", and Cancel in the uninstaller.

e2e/COVERAGE.md maps every feature to its test.

The tests really install Notepad4, replace Windows Notepad for a while and uninstall again:

• Throwaway machines only: they refuse to start without E2E_INSTALL=1.
• CI: the e2e job runs them on windows-2022 and windows-2025, which cover the pre-Windows 11 branch and the Windows 11 branch of the installer.
• Locally: on a disposable Windows VM with Git Bash, NSIS and Python on PATH, run E2E_INSTALL=1 bash scripts/e2e.sh. Output goes to $ARTIFACTS.
• Anywhere else the script stops after the two compiles.

Updating to a new Notepad4 release

The version is part of the script name, the payload folder name and two defines; the installer file name follows from them.

1. Download Notepad4_en_x64_<version>.zip (not the HD build) from the Notepad4 releases and check its SHA-256 against the release asset digest.
2. git mv Notepad4_en_x64_<old> Notepad4_en_x64_<new> and replace its six files with the zip's:
   • Notepad4.exe, matepath.exe and License.txt;
   • the *.ini-default files renamed to *.ini (Notepad4.ini, matepath.ini, Notepad4 DarkTheme.ini).
   • Give License.txt a UTF-8 BOM (printf '\xef\xbb\xbf' | cat - License.txt > l && mv l License.txt), otherwise the license page shows ©; the screenshot tour checks it.
   • If the release's file set changed, adjust the File, CopyFiles and Delete lines in the script.
3. git mv Notepad4_en_x64_<old>.nsi Notepad4_en_x64_<new>.nsi and update the defines at the top: BUNDLED_VERSION must equal the GitHub release tag exactly (e.g. v26.10r6392; the online fetch compares the two), RELEASEVERSION is en_x64_<tag>.
4. Replace every <old> in this README (grep -n <old> README.md): bundled version, silent-install and build output file names, build command, License.txt link.
5. makensis -WX Notepad4_en_x64_<new>.nsi must pass. The workflows find the script as Notepad4_en_x64_*.nsi and need no change.

Screenshots

All installer and uninstaller pages: docs/screenshots.

The images come from an automated tour: scripts/docs-screenshots.sh compiles the installer and runs scripts/docs-tour.ps1, which clicks through every page via UI Automation, checks each page's heading and captures the window. The tour really installs and uninstalls Notepad4, so it only runs on throwaway Windows machines and refuses to start without DOCS_TOUR_INSTALL=1.

To regenerate: Actions → Docs screenshots → Run workflow, unzip the docs-screenshots artifact into docs/screenshots/, run oxipng -o 4 --strip safe docs/screenshots/*.png, review the diff and commit. On a disposable Windows VM with Git Bash and NSIS on PATH: DOCS_TOUR_INSTALL=1 bash scripts/docs-screenshots.sh. CI runs the same tour as part of the E2E suite on every push (artifacts e2e-windows-*, folder screenshots/).

License

The installer script is MIT-licensed (LICENSE). Notepad4 and matepath are distributed under their own license, shown on the installer's first page (License.txt).