[BUG + GUIDE] Cowork on Windows hangs on "Setting up Claude's workspace" — CoworkVMService signature verification failure

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?

Claude Desktop's Cowork feature hangs indefinitely on "Setting up Claude's workspace" on Windows for many users. The root cause is a chain of undocumented installation requirements that the standard ClaudeSetup.exe installer does not handle correctly for existing users or non-enterprise installs. This issue documents the full failure chain and a working fix.

cowork-windows-setup-issue.md

What Should Happen?

Successful install with no hang up's or dome sort of notification of any errors.

Error Messages/Logs

Steps to Reproduce

All is in the attached md file

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Desktop 1.1.7714.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_