[BUG] Claude Desktop (Windows/MSIX) — stale file lock on WindowsApps package, only full reboot resolves it

Summary

After Claude Desktop closes (or after an in-app update), a stale file lock remains on the MSIX package executable under C:\Program Files\WindowsApps\Claude_1.2773.0.0_x.... Attempting to reopen the app results in:

"Aktualnie inny program korzysta z tego pliku." / "Another program is currently using this file."

Only a full Windows reboot clears the lock. All other workarounds fail.

Environment

• OS: Windows 11 Pro 10.0.26200
• Claude Desktop version: 1.2773.0.0 (MSIX / Windows Store install)
• Install location: C:\Program Files\WindowsApps\Claude_1.2773.0.0_x...

Steps to reproduce

1. Open Claude Desktop normally
2. Close it (via X button or system tray → Quit)
3. Attempt to reopen Claude Desktop
4. Error dialog appears: "Another program is currently using this file"

Workarounds attempted (all failed)

• Stop-Service CoworkVMService -Force — service stops but lock persists
• Stop-Process -Name 'cowork-svc' -Force — process killed but lock persists
• Restart-Service AppXSvc -Force — MSIX service restarted but lock persists
• Killing all claude.exe / cowork-svc processes via Task Manager — lock persists
• Full Windows reboot — resolves the issue ✓

Root cause (suspected)

The Electron/Squirrel updater or CoworkVMService does not fully release its file handle on the .exe before exiting. Windows retains the lock at the kernel level even after the owning process terminates. Since no process owns the handle, it cannot be released without a reboot.

This happens every time Claude Desktop is closed, not only after updates — making normal daily usage extremely disruptive.

Related issues

• #45896 — Stale file lock after in-app update (closed as "not planned")
• #42776 — Orphaned process file lock on relaunch
• #40645 — "File is busy" error after update

Request

Please reopen / re-prioritize this. Closing #45896 as "not planned" is not acceptable when the bug makes Claude Desktop unusable on Windows without rebooting after every session. At minimum, the app should ensure all handles are closed before the process exits, and/or CoworkVMService should be stopped gracefully on shutdown.

🤖 Reported via Claude Code