[BUG] Cowork fails with "Access is denied" named pipe conflict — old da-desktop install blocks new MSIX

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?

Environment

• OS: Windows 11 Pro
• Claude Desktop (MSIX): 1.3109.0.0
• Previous install: da-desktop (legacy installer)

What's Wrong

Cowork fails with "Request timed out: configure" because the old
da-desktop installation leaves cowork-svc.exe running, which takes
ownership of \\.\pipe\cowork-vm-service before the new MSIX version
can create it.

What Should Happen?

Root Cause

Two Claude installations coexist silently:

• New MSIX: C:\Program Files\WindowsApps\Claude_1.3109.0.0_x64__pzs8sxrjxfjjc\
• Old install: C:\Users\<user>\AppData\Local\Programs\da-desktop\

The old cowork-svc.exe starts with Windows and holds the named pipe.
The new CoworkVMService then fails with "Access is denied" trying to
create the same pipe

Error Messages/Logs

## Evidence
Running this confirms the conflict:
Get-Process | Where-Object { $_.Name -like "*cowork*" }
→ cowork-svc.exe from da-desktop path

[System.IO.Directory]::GetFiles("\\.\pipe\") | Where-Object { $_ -like "*cowork*" }
→ \\.\pipe\cowork-vm-service (held by old process)

Steps to Reproduce

Steps to Reproduce

1. Have a previous Claude Desktop installation (da-desktop / legacy

installer) installed on Windows 11 Pro

1. Install the new Claude Desktop MSIX from https://claude.com/download

without uninstalling the previous version first

1. Open Claude Desktop and attempt to use Cowork
2. Cowork shows "Request timed out: configure" on every attempt

Verification steps that reveal the conflict

Run in PowerShell as Administrator:

Check for old cowork-svc.exe running from da-desktop

Get-Process | Where-Object { $_.Name -like "cowork" } | Select-Object Id, Name, Path

Expected output showing conflict:

Id Name Path

---- ---- ----

4388 cowork-svc C:\Users\<user>\AppData\Local\Programs\da-desktop\resources\native\cowork-svc.exe

Confirm it holds the named pipe

[System.IO.Directory]::GetFiles("\\.\pipe\") | Where-Object { $_ -like "cowork" }

Expected output:

\\.\pipe\cowork-vm-service

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop (MSIX): 1.3109.0.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Fix

Kill PID of old cowork-svc.exe and remove da-desktop folder:
Stop-Process -Name "cowork-svc" -Force
Remove-Item "$env:LOCALAPPDATA\Programs\da-desktop" -Recurse -Force

Cowork works immediately after.

Expected behavior

The new MSIX installer should detect and remove da-desktop before
installing, or at minimum warn the user.

Related issues

Likely root cause for many open Windows Cowork issues including
named pipe access denied errors.

Workaround (until fixed)

For users hitting this issue, the immediate fix is:

1. Open PowerShell as Administrator
2. Kill the old process:

Stop-Process -Name "cowork-svc" -Force

1. Remove the old installation:

Remove-Item "$env:LOCALAPPDATA\Programs\da-desktop" -Recurse -Force

1. Restart Claude Desktop — Cowork will work immediately.