[BUG] Cowork tab shows "Virtualization not enabled" false positive warning — Cowork works fully despite the error

[mw-private]

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?

What's Wrong?

Every time I navigate to the Cowork tab in Claude Desktop, the following error banner is displayed:

"Claude's workspace requires hardware virtualization. Enable virtualization in your computer's BIOS/UEFI settings, then restart."

However, Cowork works completely and fully despite this warning. All features are available, the workspace initializes correctly, and tasks execute without any issues. The error message is a false positive — it appears to be a detection bug in the virtualization pre-check, not an actual system problem.

This is meaningfully different from the related issues #27316, #27384, #27420, #29887, etc., where Cowork also fails to function. In my case, Cowork is fully operational — only the warning is incorrect.

Environment

Property	Value
Claude Desktop Version	1.11187.1 (370d3b)
Install source	claude.ai/download (direct download, not Microsoft Store)
OS	Windows 11 Pro 24H2
Host environment	VirtualBox VM with Nested VT-x/AMD-V enabled
Virtualization in VM settings	Enabled
Cowork functional	✅ Yes, fully working

Steps to Reproduce

1. Install Claude Desktop v1.11187.1 from claude.ai/download on Windows 11 Pro 24H2 running inside a VirtualBox VM
2. Ensure Nested VT-x/AMD-V is enabled in VirtualBox VM settings
3. Open Claude Desktop and navigate to the Cowork tab
4. Observe: "Hardware virtualization required" error banner appears immediately
5. Observe: Despite the warning, Cowork initializes and works correctly

Expected Behavior

If Cowork can start and function correctly, no error banner should be shown. The virtualization pre-check should either accurately detect the working environment or be suppressed when the VM successfully starts.

Actual Behavior

A misleading BIOS/UEFI error banner is permanently displayed on the Cowork tab on every visit, even though Cowork is fully functional. This causes unnecessary confusion and may lead users to perform unnecessary BIOS changes or reinstalls.

Additional Notes

• This appears to be a false positive in the virtualization detection logic, not a real system issue
• The error message directing users to "Enable virtualization in BIOS" is particularly misleading since the workspace is actually running fine
• Related to the broader detection bug family: [BUG] Cowork shows "Virtualization is not enabled" on Windows 10 Pro despite Hyper-V fully enabled #27316, [BUG] Cowork "Virtualization is not enabled" error despite hypervisor active — regression on Windows 11 Home 25H2 #27384, [BUG] Cowork shows "Virtualization is not enabled" on Windows 11 despite Hyper-V fully enabled (Lenovo ThinkPad) #27420, [BUG] Cowork says "Virtualization is not available" — but Hyper-V is alive and well. Claude just won't believe it. #29532, [BUG] Cowork shows "Virtualization is not enabled" on Windows 10 Home despite all virtualization features enabled #29887 — but distinct in that Cowork does work in this case

What Should Happen?

What's Wrong?

Every time I navigate to the Cowork tab in Claude Desktop, the following error banner is displayed:

"Claude's workspace requires hardware virtualization. Enable virtualization in your computer's BIOS/UEFI settings, then restart."

However, Cowork works completely and fully despite this warning. All features are available, the workspace initializes correctly, and tasks execute without any issues. The error message is a false positive — it appears to be a detection bug in the virtualization pre-check, not an actual system problem.

This is meaningfully different from the related issues #27316, #27384, #27420, #29887, etc., where Cowork also fails to function. In my case, Cowork is fully operational — only the warning is incorrect.

Environment

Property	Value
Claude Desktop Version	1.11187.1 (370d3b)
Install source	claude.ai/download (direct download, not Microsoft Store)
OS	Windows 11 Pro 24H2
Host environment	VirtualBox VM with Nested VT-x/AMD-V enabled
Virtualization in VM settings	Enabled
Cowork functional	✅ Yes, fully working

Expected Behavior

If Cowork can start and function correctly, no error banner should be shown. The virtualization pre-check should either accurately detect the working environment or be suppressed when the VM successfully starts.

Actual Behavior

A misleading BIOS/UEFI error banner is permanently displayed on the Cowork tab on every visit, even though Cowork is fully functional. This causes unnecessary confusion and may lead users to perform unnecessary BIOS changes or reinstalls.

Additional Notes

• This appears to be a false positive in the virtualization detection logic, not a real system issue
• The error message directing users to "Enable virtualization in BIOS" is particularly misleading since the workspace is actually running fine
• Related to the broader detection bug family: [BUG] Cowork shows "Virtualization is not enabled" on Windows 10 Pro despite Hyper-V fully enabled #27316, [BUG] Cowork "Virtualization is not enabled" error despite hypervisor active — regression on Windows 11 Home 25H2 #27384, [BUG] Cowork shows "Virtualization is not enabled" on Windows 11 despite Hyper-V fully enabled (Lenovo ThinkPad) #27420, [BUG] Cowork says "Virtualization is not available" — but Hyper-V is alive and well. Claude just won't believe it. #29532, [BUG] Cowork shows "Virtualization is not enabled" on Windows 10 Home despite all virtualization features enabled #29887 — but distinct in that Cowork does work in this case

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Install Claude Desktop v1.11187.1 from claude.ai/download on Windows 11 Pro 24H2 running inside a VirtualBox VM
2. Ensure Nested VT-x/AMD-V is enabled in VirtualBox VM settings
3. Open Claude Desktop and navigate to the Cowork tab
4. Observe: "Hardware virtualization required" error banner appears immediately
5. Observe: Despite the warning, Cowork initializes and works correctly

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

Version 1.11187.1 (370d3b)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response

[github-actions]

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