[BUG] [Cowork] Windows: VM fails to start with 0x80070057 "Microsoft Virtual BIOS" error + macOS network diagnostics commands

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?

Cowork fails to start the VM on Windows with HCS error 0x80070057 ("El parámetro no es correcto." / "The parameter is incorrect."). The failure occurs during Virtual BIOS initialization (PowerOnCold phase). Additionally, the network diagnostics module attempts to run macOS-specific commands (/sbin/ifconfig, /usr/sbin/scutil, /usr/bin/pgrep, /usr/sbin/kextstat, /usr/bin/log) which obviously fail on Windows.

Related to #24974 (different HCS error code but same macOS diagnostics bug).

cowork_vm_node.log

What Should Happen?

The Cowork VM should start successfully and provide a functional workspace environment on Windows.

Error Messages/Logs

[VM:start] VM boot failed: HCS operation failed: failed to start VM: HcsWaitForOperationResult failed with HRESULT 0x80070057
VirtualDeviceFailure: PowerOnCold - Microsoft Virtual BIOS (AC6B8DC1-3257-4A70-B1B2-A9C9215659AD)
[networkDiagnostics] Failed to spawn /sbin/ifconfig: spawn /sbin/ifconfig ENOENT
[networkDiagnostics] === Comprehensive macOS Diagnostics === (running on Windows)
[VM:start] Skipping auto-reinstall (already attempted once)

Steps to Reproduce

1. Install Claude Desktop for Windows (v1.1.3541)
2. Open Cowork tab
3. Observe VM bundle downloads successfully (all files present including sessiondata.vhdx)
4. VM fails to start immediately with HCS 0x80070057 error
5. Auto-reinstall is attempted once and then blocked

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

1.1.3541

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

System: Intel Core i7-14700 | 64GB DDR5 | RTX 4080 Super
Hyper-V: fully enabled (all 10 features)
Secure Boot: enabled in UEFI (Windows UEFI mode)
Test Gen2 VM created manually starts successfully — Hyper-V works correctly.
All VM bundle files present including sessiondata.vhdx.
Troubleshooting performed: cleared HCS registry keys, reinstalled Claude Desktop from scratch, multiple reboots.