[BUG] /desktop fails on Windows when Claude Desktop is installed as MSIX/Store package (refile of #36079)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet (an earlier report — #36079 — was auto-closed by the stale-bot on 2026-04-16 with the explicit instruction "Please open a new issue if this is still relevant." That issue is now auto-locked, so this is a refile per the bot's instruction).
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

/desktop fails on Windows when Claude Desktop is installed as an MSIX/Appx package — which is the delivery method when installing from https://claude.ai/download today.

The launcher appears to look for either:

• A Win32 install at %LocalAppData%\AnthropicClaude\app-X.X.X\claude.exe (or similar Squirrel path), or
• A classic HKCR:\claude\shell\open\command registry key.

Neither exists for MSIX installs:

• The binary lives at C:\Program Files\WindowsApps\Claude_<ver>_x64__pzs8sxrjxfjjc\app\Claude.exe — a protected directory that user-space processes can't enumerate.
• The MSIX package registers the claude:// URI handler through its manifest's windows.protocol extension (URI Activation), not via a classic shell\open\command key — so neither HKCR:\claude\shell\open\command nor HKCU:\Software\Classes\claude\shell\open\command exists.

Despite the failure, Windows URI activation for the claude:// scheme is fully working — see verification below.

What Should Happen?

/desktop opens Claude Desktop and hands off the current session.

As a fallback when no Win32 install / HKCR:\claude registration is found, the launcher should ShellExecute the claude://... URL (or cmd /c start "" "claude://..."). Windows will route the URI activation through whichever handler is registered — MSIX or Win32 — and the MSIX package's protocol extension handles it correctly.

Error Messages/Logs

Failed to open Claude Desktop. Please try opening it manually.

Steps to Reproduce

1. Install Claude Desktop on Windows by downloading from https://claude.ai/download (delivered as an MSIX/Appx package).
2. Confirm install — Get-AppxPackage -Name "*Claude*" returns Claude_pzs8sxrjxfjjc and the executable is at C:\Program Files\WindowsApps\Claude_<ver>_x64__pzs8sxrjxfjjc\app\Claude.exe.
3. Confirm URI activation works — Start-Process "claude://" from PowerShell launches the app.
4. Run /desktop in Claude Code CLI → fails with the message above.

Diagnostic Evidence (collected on my machine)

• Running Claude Desktop process path: C:\Program Files\WindowsApps\Claude_1.7196.1.0_x64__pzs8sxrjxfjjc\app\Claude.exe (confirmed via Get-Process and Get-CimInstance Win32_Process).
• Package family name: Claude_pzs8sxrjxfjjc (AUMID: Claude_pzs8sxrjxfjjc!Claude).
• Manifest declares claude protocol: Get-AppxPackage Claude | manifest read shows windows.protocol extension with Name="claude".
• No Claude.exe under any of: %LocalAppData%\Programs\claude, %LocalAppData%\AnthropicClaude, %ProgramFiles%\Claude, %ProgramFiles(x86)%\Claude.
• No Claude* entry in Windows uninstall registry (HKLM\...\Uninstall or HKCU\...\Uninstall).
• reg query "HKCR\claude\shell\open\command" → "The system was unable to find the specified registry key or value."
• Start-Process "claude://" → succeeds, brings the running Claude Desktop to focus.

Suggested Fix

When the existing Win32-path / HKCR:\claude detection fails on Windows, fall back to ShellExecute (or cmd /c start "" "claude://...") on the claude:// URL with the session payload. Windows resolves the URI activation through whichever handler is registered — MSIX or Win32. As a belt-and-braces option, also detect MSIX installs via Get-AppxPackage (package name Claude, family Claude_pzs8sxrjxfjjc) for a clearer "found"/"not found" signal in error messages.

Claude Code Version

2.1.143

Platform

Anthropic API

Operating System

Windows 11 Home 10.0.26200

Terminal/Shell

PowerShell 7

Additional Information

• Claude Desktop package: Claude_1.7196.1.0_x64__pzs8sxrjxfjjc (MSIX, installed via the installer downloaded from https://claude.ai/download)
• Related: #36079 (original report, auto-closed by stale-bot 2026-04-16, locked 2026-04-23)