Cowork "Virtualization is not available" on Windows 11 Pro 25H2 despite all features enabled

[CarosYM]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

OS: Windows 11 Pro Version 25H2 (Build 26200.8037)
Claude Desktop: latest version
Features enabled:

Virtual Machine Platform ✅
Windows Hypervisor Platform ✅
Hyper-V ✅
ran bcdedit /set hypervisorlaunchtype auto ✅

What Should Happen?

Cowork should detect that virtualization is enabled and successfully initialize the workspace VM.

Error Messages/Logs

Error message: "La virtualización no está disponible — El espacio de trabajo de Claude requiere Virtual Machine Platform, pero el servicio de virtualización no responde."

Steps to Reproduce

Enable Hyper-V, Virtual Machine Platform, and Windows Hypervisor Platform in Windows Features
Run bcdedit /set hypervisorlaunchtype auto in PowerShell as administrator
Restart computer
Open Claude Desktop and navigate to Cowork tab
Error appears immediately

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

No response

Claude Code Version

Claude 1.1348.0 (efa3fd) 2026-04-08T15:06:08.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

No response

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Cowork "Virtualization is not available" on Windows 11 Pro 25H2 despite Hyper-V fully enabled #44133
2. [BUG] Virtualization is not available: Claude's workspace requires Virtual Machine Platform, but the virtualization service isn't responding. Restart your computer to resolve this. #45446
3. [BUG] Cowork shows "Virtualization is not available" on Windows 11 Pro despite Hyper-V fully enabled and services running** #32574

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
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🤖 Generated with Claude Code

[ibarjoaco]

This is not a duplicate — I am experiencing the same bug and adding my case to increase visibility. Please keep this open.

[Ogyiesworld]

Confirmed reproduction on Windows 11 Enterprise + Credential Guard

Hitting the same issue on Claude Desktop 1.1617.0 (8d6345). VBS/Credential Guard is consuming firmware virtualization before cowork can access it.

System: Lenovo ThinkPad 21H3001HUS, Windows 11 Enterprise 24H2 (Build 26100)

From %APPDATA%\Claude\logs\cowork_vm_node.log:

[VM:start] HCS error detected, firmwareVirt=false, sentinel=HYPERVISOR_VIRT_DISABLED

Diagnostic output:

HyperVisorPresent             : True
VirtualizationFirmwareEnabled : False
VMMonitorModeExtensions       : False

VBSStatus       : Running
CredentialGuard : True
HVCI            : True

All Hyper-V features enabled (VirtualMachinePlatform, HypervisorPlatform, Microsoft-Hyper-V-All). Physical machine, not a VM. VirtualizationFirmwareEnabled=False on physical hardware points to VBS holding the firmware virt exclusively.

Disabling Credential Guard isn't a viable workaround on managed enterprise machines — it exposes domain credentials to LSASS dumping. This will likely affect any enterprise environment with Credential Guard enforced via Group Policy.

Happy to provide additional diagnostics if this analysis is off.

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.