[BUG] [Cowork] Windows: sessiondata.vhdx not created + network diagnostics uses macOS 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 on Windows fails to start with two distinct issues:

Issue 1: sessiondata.vhdx is never created during VM setup

The VM bundle downloads successfully (100% progress bar), but the sessiondata.vhdx file is never created. The VM then fails to start with:

HCS operation failed: failed to start VM: HcsWaitForOperationResult failed with HRESULT 0x80070002
"Die Anlage C:\Users\<user>\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\sessiondata.vhdx wurde aufgrund eines Fehlers nicht gefunden"

The VM bundle directory contains:

initrd              (175 MB)
rootfs.vhdx         (9.4 GB)
smol-bin.vhdx       (37 MB)
vmlinuz             (14 MB)
.initrd.origin
.rootfs.vhdx.origin
.vmlinuz.origin

sessiondata.vhdx is missing. It is never generated during the setup process.

Manually creating the VHD via New-VHD -Path "...\sessiondata.vhdx" -SizeBytes 2GB -Dynamic resolves the missing file error but leads to Issue 2.

Issue 2: Network diagnostics uses macOS commands on Windows

After manually creating the sessiondata.vhdx, the VM boots but times out after 60 seconds. The cowork_vm_node.log reveals that the network diagnostics module is calling macOS-specific binaries on Windows:

[networkDiagnostics] === Comprehensive macOS Diagnostics ===
[networkDiagnostics] Failed to run /sbin/ifconfig: spawn /sbin/ifconfig ENOENT
[networkDiagnostics] Failed to run /usr/sbin/scutil: spawn /usr/sbin/scutil ENOENT
[networkDiagnostics] Failed to run /usr/bin/pgrep: spawn /usr/bin/pgrep ENOENT
[networkDiagnostics] Failed to run /usr/sbin/kextstat: spawn /usr/sbin/kextstat ENOENT
[networkDiagnostics] Failed to run /usr/bin/log: spawn /usr/bin/log ENOENT

The log literally says "Comprehensive macOS Diagnostics" while running on Windows. It appears the macOS network initialization code was shipped to Windows without platform-specific adaptation, which likely causes the VM networking to fail entirely.

What Should Happen?

1. sessiondata.vhdx should be automatically created during the VM bundle setup on Windows (similar to sessiondata.img on macOS).
2. Network diagnostics should use Windows commands (ipconfig, Get-VpnConnection, Get-NetAdapter, etc.) instead of macOS commands (/sbin/ifconfig, /usr/sbin/scutil, /usr/sbin/kextstat).
3. The VM should successfully boot and establish a connection on Windows.

Error Messages/Logs

### Missing sessiondata.vhdx error:

HCS operation failed: failed to start VM: HcsWaitForOperationResult failed with HRESULT 0x80070002:
{"Error":-2147024894,"ErrorMessage":"Das System kann die angegebene Datei nicht finden.",
"ErrorEvents":[{"Message":"Die Anlage C:\Users\Mustafa\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\sessiondata.vhdx wurde aufgrund eines Fehlers nicht gefunden"}]}


### macOS commands on Windows (from cowork_vm_node.log):

2026-02-11 12:42:27 [warn] [networkDiagnostics] Failed to detect VPN interfaces: Error: Failed to spawn /sbin/ifconfig: spawn /sbin/ifconfig ENOENT
2026-02-11 12:42:27 [warn] [networkDiagnostics] Failed to detect connected VPNs via scutil: Error: Failed to spawn /usr/sbin/scutil: spawn /usr/sbin/scutil ENOENT
2026-02-11 12:42:27 [info] [networkDiagnostics] === Comprehensive macOS Diagnostics ===
2026-02-11 12:42:27 [error] [VM:start] Startup failed: Error: VM connection timeout after 60 seconds

Steps to Reproduce

1. Install Claude Desktop for Windows (v1.1.2685.0) with Cowork enabled
2. Ensure Hyper-V is enabled and SVM Mode is active in BIOS
3. Open Claude Desktop and switch to the Cowork tab
4. Observe the VM bundle downloading to 100%
5. VM fails to start — sessiondata.vhdx is missing from the bundle directory
6. If sessiondata.vhdx is manually created, VM boots but times out after 60 seconds due to failed network initialization

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

latest

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Troubleshooting steps already performed:

• Deleted and re-downloaded vm_bundles directory multiple times
• Reinstalled Claude Desktop
• Rebooted PC after enabling SVM Mode in BIOS
• Verified Hyper-V is enabled (Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V → State: Enabled)
• Confirmed systeminfo shows "Virtualisierung in Firmware aktiviert: Ja" (after BIOS change)
• Installed Docker Desktop (no effect)
• Manually created sessiondata.vhdx via New-VHD (resolved file-not-found error but led to connection timeout)
• Verified no VPN or proxy interfering

The root cause appears to be that the Windows port of Cowork is incomplete — the VM setup pipeline doesn't create sessiondata.vhdx, and the network diagnostics module still references macOS-only binaries.