[BUG] Cowork does not initialize on Windows Server 2022 — no VM download attempted, reinstall button unresponsive

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?

What's Wrong

Cowork never initializes on Windows Server 2022. There is no cowork_vm_node.log file, no vm_bundles directory, and the "Reinstall" button in the Cowork UI does nothing when clicked — no spinner, no download, no error feedback.

The main log shows YukonSilver received its config but immediately set autoDownloadInBackground=false, meaning the VM download was never attempted.

Regular Chat mode works perfectly. Only Cowork is affected.

Environment

• OS: Windows Server 2022 (Build 10.0.20348)
• Claude Desktop version: 1.1.4010 (da63f3)
• Hyper-V: Available but not installed (Server role, not enabled due to IT policy constraints on shared infrastructure)
• Subscription plan: Team
• Install method: Direct download from claude.com/download (Microsoft Store not available on Server)

Steps to Reproduce

1. Install Claude Desktop on Windows Server 2022 via direct download
2. Open Claude Desktop — Cowork tab is visible
3. Click the Cowork tab
4. Cowork shows an error or prompt to reinstall
5. Click "Reinstall" — nothing happens. No spinner, no download, no error message.

Expected Behavior

Clicking "Reinstall" should either:

• Download and initialize the Cowork VM workspace, or
• Display a clear error message explaining why Cowork cannot run on this platform (e.g., "Hyper-V is required" or "Windows Server is not supported")

Evidence

No VM files exist

The %APPDATA%\Claude directory contains no Cowork-related files:

• No cowork_vm_node.log in the logs directory
• No vm_bundles folder anywhere
• Only main.log, claude.ai-web.log, and unknown-window.log exist in logs

main.log shows YukonSilver declined to start

2026-02-12 18:32:19 [info] [warm] Waiting for YukonSilverConfig before warm download (version: 1.1.2998)
2026-02-12 18:32:19 [info] [warm] YukonSilverConfig received, autoDownloadInBackground=false

Hyper-V status on Windows Server 2022

Name               InstallState
----               ------------
Hyper-V               Available
RSAT-Hyper-V-Tools    Available
Hyper-V-Tools         Available
Hyper-V-PowerShell    Available

On Windows Server, "Available" means the role exists but is not installed. Unlike Windows 11 Home where Hyper-V is absent entirely, Server 2022 fully supports Hyper-V — but enabling it requires IT approval and a server reboot, which may not be feasible on shared/managed infrastructure.

Key Issue

Windows Server 2022 is not mentioned anywhere in the Cowork documentation as either supported or unsupported. The Cowork tab appears in the UI (suggesting the feature flag is active), but the backend silently refuses to initialize.

If Windows Server is not supported, users should see a clear message instead of a dead reinstall button.

If Windows Server could be supported, it is worth noting that Server 2022 has full Hyper-V capability — it just may not be enabled by default on managed infrastructure.

Related Issues

• #25136 — Cowork tab not showing, yukonSilver marked unsupported (Windows 11 Pro)
• #24918 — Cowork cannot connect to API (Windows 11 Home)
• #25205 — Cowork tab disappears on restart, VM bundle deleted
• #26090 — Cowork tab not showing on Windows 10 Home

What Should Happen?

The Cowork button should complete the update.

Error Messages/Logs

Steps to Reproduce

1. I clicked the update option for Cowork.
2. Nothing happens.

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Version 1.1.4010 (da63f3)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_