Fix: MCP Windows-MCP spawn uv ENOENT (Claude Desktop / Cowork)

Problem

When using Claude Desktop with Cowork or MCP servers, you may encounter the following errors:

MCP Windows-MCP: spawn uv ENOENT
MCP Windows-MCP: Server disconnected

In some cases, you may also see:

Reinstall required (Cowork requires Claude Desktop…)

Root Cause

The error spawn uv ENOENT means that the system attempted to execute the uv command, but Windows could not locate it.

This typically occurs when:

• uv is not installed
• uv is installed but not available in the system PATH
• Claude Desktop cannot access the PATH environment

Step 1 — Verify Installation

Open PowerShell and run:

uv --version
where.exe uv

If you receive an error such as:

The term 'uv' is not recognized...

then uv is not installed.

Step 2 — Install uv

If winget is available:

winget install --id=astral-sh.uv -e

If winget is not available, use the official installer:

powershell -ExecutionPolicy Bypass -c "irm https://astral.sh/uv/install.ps1 | iex"

Step 3 — Restart Shell

Close PowerShell completely and open a new window. Then verify again:

uv --version
where.exe uv

You should now see a version and a path to uv.exe.

Step 4 — If uv Is Still Not Found

Check common install locations:

Test-Path "$env:USERPROFILE\.local\bin\uv.exe"
Test-Path "$env:USERPROFILE\AppData\Roaming\uv\bin\uv.exe"

If one returns True, test directly:

& "$env:USERPROFILE\.local\bin\uv.exe" --version

Step 5 — Add uv to PATH Manually

If the executable works but is not globally available, add it to PATH:

[Environment]::SetEnvironmentVariable(
  "Path",
  $env:Path + ";$env:USERPROFILE\.local\bin",
  "User"
)

Then restart PowerShell and verify again.

Step 6 — Update MCP Configuration

Even if uv works in PowerShell, Claude Desktop may still not detect it.

It is recommended to use the absolute path to uv.exe in your MCP configuration.

Example:

{
  "mcpServers": {
    "windows-mcp": {
      "command": "C:\\Users\\YourUser\\.local\\bin\\uv.exe",
      "args": [
        "run",
        "windows-mcp"
      ]
    }
  }
}

Replace the path with the one returned by:

where.exe uv

Step 7 — Reboot and start Claude Desktop

After installation and configuration:

• Reboot Windows
• Reopen the application

Notes

• The "Server disconnected" message is a secondary error caused by the failure to start uv
• The "Reinstall required" message may persist until Claude Desktop is restarted or reinstalled

Summary

If you encounter the error:

spawn uv ENOENT

it means that uv is not installed or not accessible.

Installing uv and ensuring it is correctly referenced in the MCP configuration resolves the issue.

Checklist

• uv is installed
• uv is accessible via PATH or full path is used
• MCP config points to correct executable
• Claude Desktop has been restarted