[Windows] Workspace fails to start - tries to mount non-existent D: drive via Plan9 share

Bug Description

Claude Desktop's workspace fails to start on Windows when the system only has a C: drive. The workspace initialization attempts to mount a D: drive via Plan9 share that does not exist.

Error Message

Failed to start Claude's workspace
failed to add Plan9 share 'd': HcsWaitForOperationResult failed with HRESULT 0x80070003:
{"Error":-2147024893,"ErrorMessage":""}

HRESULT 0x80070003 = "The system cannot find the path specified."

Steps to Reproduce

1. Have a Windows machine with only a C: drive (no D: drive)
2. Open Claude Desktop and start a conversation that triggers the workspace
3. Workspace fails to start with the above error

What I've Tried

• Restarting Claude Desktop
• Reinstalling the workspace via the "reinstall the workspace" link in the error dialog
• Neither resolved the issue

Expected Behavior

The workspace should only attempt to mount drives that actually exist on the system.

Environment

• OS: Windows 11 Enterprise 10.0.26100
• Drives: C: only (no D: drive)

Screenshot

The error appears as a modal dialog in the Claude Desktop app.