[BUG] Cowork VM stuck at boot on Windows — recurring, blocks all shell/code work

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?

Hello Anthropic Support team,

I'm writing to report a recurring, blocking issue with Claude Cowork on Windows that I have not been able to resolve despite extensive troubleshooting. I am a paying Claude user and rely on Cowork for my work building educational materials for my English academy.

Summary

The Cowork Linux workspace fails repeatedly with "Workspace unavailable" / "워크스페이스가 사용 불가" errors. File tools work, but bash and code execution do not. This has happened across multiple sessions over an extended period — it is not a one-time issue.

Environment

• OS: Windows (home desktop, primary work machine)
• Claude Desktop install type: Direct install (not Microsoft Store) — VM bundle located at %APPDATA%\Claude\vm_bundles
• Account: paying consumer plan
• Use case: small private English academy (Kids in Wonder, South Korea) — building Word documents, presentations, classroom materials

What I think is happening

The service-level configuration is fine and intentionally locked down. The actual failure appears to be at the VM boot / guest userspace stage, which I as a user cannot diagnose without access to the cowork-service.log or guest VM logs.

This matches the pattern in several open GitHub issues, particularly #54011 (VM never reaches userspace) and #25206 (VM starts but service unrecoverable on Windows 11 Pro).

What I need

1. A reliable, durable fix — not another workaround that breaks after a Windows update or reboot
2. If a fix isn't immediately available, guidance on whether to uninstall and reinstall Claude Desktop completely, or whether that will just trigger the same issue
3. Information on how I can capture useful diagnostic logs (cowork-service.log location, etc.) to help your engineers if needed

This issue has been blocking my work for some time. I would very much appreciate prompt attention. Happy to provide any additional logs or run any diagnostic commands you need.

Thank you,
Maria
Director, Kids in Wonder English Academy
South Korea

What Should Happen?

Claude cowork should create word docs and organize files on desktop

Error Messages/Logs

## Symptoms

1. Inside Cowork, Claude reports: "Linux 워크스페이스가 사용 불가 상태" / "워크스페이스 bash가 사용 불가 상태" — falls back to telling me to run PowerShell scripts manually
2. After today's reset attempt, the VM now hangs at boot — Claude inside Cowork explicitly says: "Linux workspace is stuck booting, normally takes 10-30 seconds but is taking much longer"
3. File tools continue to work; only the Linux sandbox / bash is affected
4. Issue recurs after seemingly being resolved — not a stable fix between sessions

Steps to Reproduce

Troubleshooting steps already performed today (all in admin PowerShell, verified True for IsInRole Administrator)

1. Verified CoworkVMService status: Running, StartType Automatic — service is healthy
2. Attempted to modify service config (Set-Service, sc config, sc failure) — all denied with Access Denied (error 5) despite admin rights
3. Checked service ACL via sc.exe sdshow CoworkVMService:

D:(A;;CCLCSWRPWPDTLOCRRC;;;AU)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;S-1-5-80-1949724575-2387902436-65106593-1201171665-3967308604)S:(AU;FA;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;WD)
— confirms Built-in Administrators (BA) has no write permissions; only the service SID and SYSTEM can modify. This appears to be intentional Anthropic security design.

1. Attempted to add BA to ACL via sc.exe sdset — also denied
2. Stopped CoworkVMService (this permission is granted), deleted VM bundle directory at %APPDATA%\Claude\vm_bundles, killed cowork-vm via hcsdiag, removed cowork-vm-nat HNS network, restarted service — all completed successfully without errors
3. Reopened Claude Desktop — VM bundle re-extracted, but VM now hangs indefinitely at boot stage instead of reaching userspace

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.121.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_