[BUG] Cowork "Virtual Machine Platform not available" — VM never initializes, no logs created, UAC ShellExecuteExW error

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?

What's Wrong?
Cowork shows "Virtual Machine Platform not available" with error
"ShellExecuteExW failed — UAC may have been denied". After enabling
VMP via DISM and restarting, the error persists. The VM never
initializes — %APPDATA%\Claude\logs\cowork_vm_node.log does not exist.

Environment

• OS: Microsoft Windows 11 Pro
• Image Version: 10.0.26100.7623
• Subscription: Pro
• VirtualMachinePlatform: Enabled (confirmed via Get-WindowsOptionalFeature)
• CoworkVMService: Running
• %APPDATA%\Claude\logs folder: Does not exist

Steps Taken

1. Stopped CoworkVMService and deleted vm_bundles folder
2. Ran DISM to enable VirtualMachinePlatform, HypervisorPlatform,

Microsoft-Hyper-V — all returned "The operation completed successfully"

1. Restarted PC
2. Ran Claude Desktop as Administrator
3. VMP confirmed Enabled via PowerShell
4. cowork_vm_node.log does not exist — VM never attempts to start

Expected: Cowork detects VMP is enabled and initializes the workspace
Actual: Persistent "Virtual Machine Platform not available" error
with ShellExecuteExW UAC failure, no logs generated

Related issues: #41633, #32004, #29887, #27420

What Should Happen?

Cowork should detect that Virtual Machine Platform is enabled and successfully initialize the VM workspace, allowing access to the Cowork tab.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Desktop on Windows 11 Pro
2. Open Claude Desktop and navigate to the Cowork tab
3. Click the in-app button to enable Virtual Machine Platform — gets stuck at 95%
4. Manually enable VMP, HypervisorPlatform, and Microsoft-Hyper-V via DISM (all succeed)
5. Restart PC
6. Run Claude Desktop as Administrator
7. Navigate to Cowork tab — "Virtual Machine Platform not available" error with "ShellExecuteExW failed — UAC may have been denied"
8. Check %APPDATA%\Claude\logs — folder does not exist, VM never initializes

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

N/A — using Claude Desktop (Cowork feature), not Claude Code CLI

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_