[BUG] Enabling Cowork triggers restart that causes Windows 11 boot failure (Secure Boot enabled)

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?

Enabling the Cowork feature in Claude Desktop prompts a restart with updates.
After that restart, Windows 11 fails to boot entirely. Requires PC recovery to resolve.
Reproduced twice — fully consistent and repeatable.

System Info:

• OS: Windows 11 25H2 (Build 26200)
• Secure Boot: On
• Claude Desktop: latest version from claude.ai/download

Actual: PC fails to boot entirely — requires recovery

Notes:

• Disabling CoworkVMService via sc.exe prevents the issue
• Cowork's VM service appears incompatible with Secure Boot on this configuration
• Normal Claude Desktop chat works fine without Cowork enabled

What Should Happen?

Expected: PC reboots normally into Windows after Cowork update

Error Messages/Logs

**Actual:** PC fails to boot entirely — requires recovery

Steps to Reproduce

Steps to Reproduce:

1. Install Claude Desktop on Windows 11 25H2 with Secure Boot enabled
2. Enable the Cowork feature in settings
3. Accept the prompted restart (updates appear to install during shutdown)
4. PC fails to boot — black screen / boot loop
5. Requires Windows recovery to restore

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.3561.0 (fbc74b) 2026-04-20T14:59:51.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_