[BUG] [Windows] Claude Desktop fails to relaunch after update — "File is busy" error, requires PC restart

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [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?

Note: This is a Claude Desktop (Windows) bug, not Claude Code CLI. Filing here as there is no separate repo for Claude Desktop.

Related issue: #31548 (same root cause — zombie processes holding file locks on Windows, but that one is about rg.exe in VS Code extension)

When Claude Desktop auto-updates and attempts to relaunch on Windows, the old process does not fully terminate. The new instance fails to start with the error dialog: "Файл занят другой программой" ("File is busy by another program").

• The old process disappears from the system tray
• It is NOT visible in Task Manager (no Claude.exe process found)
• taskkill /F /IM Claude.exe reports no process found
• But something still holds file locks, preventing the new instance from launching
• Only a full PC restart resolves the issue

Environment:

• OS: Windows 11 Pro 10.0.26200
• Claude Desktop version: 1.1.9493.0
• Install source: Microsoft Store

What Should Happen?

When Claude Desktop updates and relaunches, the old process should fully terminate and release all file locks before the new instance starts. The app should relaunch seamlessly without requiring a PC restart.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Desktop from Microsoft Store on Windows 11
2. Run the app normally
3. Wait for an auto-update to trigger a relaunch (or trigger it manually)
4. Error dialog appears: "Файл занят другой программой" ("File is busy by another program")
5. App cannot start. No Claude.exe process visible in Task Manager
6. Only a full PC restart resolves the issue

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A - This is a Claude Desktop bug (version 1.1.9493.0)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Non-interactive/CI environment

Additional Information

<img width="673" height="377" alt="Image" src="https://github.com/user-attachments/assets/77c1cb35-7267-482f-80c8-c1548a3aa9b3" />