[BUG] [BUG] Missing HCS services: vfpext — persists on HP / Windows 11 Pro after Hyper-V + VMP 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?

Preflight Checklist

• [x] I have searched existing issues (related: #74649, #77277, #78866, #80584)
• [x] This is a single bug report
• [x] I am using the latest version of Claude Desktop

What's Wrong?

The Cowork tab is disabled. Hovering shows "Missing HCS services: vfpext".
vfpext is the only missing component — vmcompute and hns are now present after
enabling the virtualization stack. It does not register even after enabling all
Hyper-V features and rebooting.

Environment

• Hardware: HP laptop
• OS: Windows 11 Pro
• CPU virtualization (VT-x): Enabled (confirmed in Task Manager)
• Hyper-V, Virtual Machine Platform, HypervisorPlatform: Enabled via

Enable-WindowsOptionalFeature (all completed successfully)

• Fast Startup: disabled

Steps to Reproduce

1. Enable VirtualMachinePlatform, Microsoft-Hyper-V -All,

Microsoft-Hyper-V-Services -All in elevated PowerShell

1. Disable Fast Startup, then Restart (not shutdown/power-on)
2. Open Claude Desktop, hover the Cowork tab

Actual

"Missing HCS services: vfpext". Get-Service vfpext returns nothing.
vmcompute and hns are present. Cowork stays disabled.

Expected

vfpext.sys should be deployed and the service registered once Hyper-V / VMP
are enabled, so Cowork can start.

What Should Happen?

vfpext.sys should be deployed and the vfpext service registered once Hyper-V and Virtual Machine Platform are enabled, so the Cowork tab becomes available and can start.

Error Messages/Logs

Steps to Reproduce

1. On an HP laptop with Windows 11 Pro and VT-x enabled, open elevated PowerShell
2. Run: Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform -All
3. Run: Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All
4. Run: Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-Services -All
5. Disable Fast Startup and reboot using Restart (not shutdown/power-on)
6. Open Claude Desktop and hover over the Cowork tab
7. Tooltip shows "Missing HCS services: vfpext" and the tab stays disabled

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.26832.0.0

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_