# Bug Report: Windows-MCP PowerShell Tool — Subprocess Hang

**Date:** 2026-03-24  
**Reporter:** mkime (TOWERPC)  
**Claude Desktop Version:** Claude 1.1.8629.0  
**OS:** Windows 11, MSI B560M PRO-VDH WIFI (MS-7D18), AMD64  
**Extension:** Windows-MCP (ant.dir.cursortouch.windows-mcp)

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## Summary

The Windows-MCP PowerShell tool hangs indefinitely (4+ minute timeout) when 
executing any command that spawns a child process. Simple built-in commands 
work fine. This makes the tool nearly unusable for real development work.

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## Behavior

### Commands that WORK (respond instantly):
- `echo "text"`
- `python --version`
- `arduino-cli version`
- `node --version`

### Commands that HANG (4+ minute timeout, never return):
- `pip --version`
- `pip list`
- `npm --version`
- `git --version` (before Git was uninstalled)
- `python -m pip --version`
- `python -c "import sys; print(sys.executable)"`
- Any PowerShell script block with loops, Write-Host with -ForegroundColor, or multiple commands

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## Reproduction Steps

1. Open Claude Desktop with Windows-MCP extension active
2. Ask Claude to run: `pip --version`
3. Tool call hangs for 4+ minutes then returns timeout error:
   "No result received from the Claude Desktop app after waiting 4 minutes"

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## What Was Tried (Did Not Fix)

- Restarted Claude Desktop completely (close from system tray)
- Removed and reinstalled Windows-MCP extension via Settings > Developer
- Reinstalled PowerShell
- Uninstalled Git for Windows (was suspected cause — git-lfs filter-process 
  spawning background process). Uninstalling Git did NOT resolve the issue.
- Rebooted machine multiple times

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## Additional Context

- Issue appeared to coincide with a recent Claude Desktop update
- Prior to this session, longer PowerShell scripts were working correctly
  (successfully ran multi-step diagnostic scripts, arduino-cli commands, 
  file operations, registry edits in previous sessions)
- The .venv folder referenced in Windows-MCP docs was NOT present at:
  C:\Users\mkime\AppData\Roaming\Claude\Claude Extensions\ant.dir.cursortouch.windows-mcp\
  suggesting the venv rebuild did not occur after reinstall
- Windows-MCP python.exe confirmed running at:
  C:\Users\mkime\AppData\Roaming\uv\python\cpython-3.13-windows-x86_64-none\python.exe

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## Impact

High. The PowerShell subprocess hang makes it impossible to:
- Run pip install commands
- Use npm
- Execute multi-line scripts
- Do any real development toolchain work via Claude Desktop

Single-word commands still work as a workaround but this is severely limited.

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## System Info
- CPU: Intel (MSI B560M board)
- RAM: 32GB (7GB in use at time of issue)
- Python: 3.14.3 (via uv)
- Node.js: v24.14.0
- arduino-cli: 1.4.1