[BUG] Cowork Windows - Cannot connect to Claude API from workspace (Windows 11 Home)

[Amumuman]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

After Cowork Windows launch (Feb 10, 2026), Cowork consistently fails to connect to the Claude API on Windows 11 Home.

The workspace attempts to start but always ends with "ワークスペースからClaude APIに接続できません" (Cannot connect to Claude API from workspace).

Regular Chat mode works perfectly. Only Cowork is affected.

Environment:

• OS: Windows 11 Home (latest updates)
• Claude Desktop: Latest version (downloaded Feb 11, 2026)
• WSL2: Installed (Ubuntu)
• Windows Features: Virtual Machine Platform ✅, Windows Hypervisor Platform ✅, Hyper-V ❌ (not available on Home)
• VPN: None
• Firewall: Windows Defender — Claude allowed on both Private and Public
• Antivirus: AhnLab Safe Transaction installed but not running during tests

What Should Happen?

Cowork workspace should start successfully and connect to the Claude API, allowing task execution — the same way regular Chat mode works without issues.

Error Messages/Logs

Error messages appear in this order:

1. "申し訳ございません。Claude APIへの接続に時間がかかっています..."
   (Taking longer than expected to connect to Claude API)

2. "Claude のワークスペースの起動に失敗しました - ワークスペースからClaude APIに接続できません"
   (Failed to start workspace - Cannot connect to Claude API from workspace)

Previously also saw (before installing WSL2):
- "お使いのコンピュータがClaudeのワークスペースへのネットワーク接続を提供していません"
  (Computer is not providing network connection to workspace)

Note: After installing WSL2, the error changed from "network not provided" to "cannot connect to API", suggesting the VM can now get network access but something still blocks the API connection.

Steps to Reproduce

1. Install Claude Desktop on Windows 11 Home (latest version, Feb 2026)
2. Open Claude Desktop
3. Switch to Cowork tab
4. Attempt to start any task
5. Wait ~60 seconds
6. Observe: "Claude APIに接続できません" error appears

Troubleshooting steps attempted (all failed):

• Reinstalled Claude Desktop twice (complete uninstall + fresh install)
• Deleted VM bundles and cache folders
• Verified Windows Defender Firewall allows Claude (Private + Public)
• Installed WSL2 via "wsl --install"
• Ran Claude Desktop as Administrator
• Reset network (netsh winsock reset, netsh int ip reset, ipconfig /flushdns)
• Disabled AhnLab Safe Transaction
• Multiple reboots

Possibly related: #18854, #18006, #24070, #17868 (all macOS, same API connection symptoms)

This is a Day 1 Windows launch issue. Would appreciate clarification on whether Windows 11 Home is officially supported or if Hyper-V (Pro/Enterprise) is required.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

Claude Desktop latest version (Windows, downloaded Feb 11, 2026). This is Cowork on Claude Desktop, not Claude Code CLI.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• This is a Cowork issue on Claude Desktop, not Claude Code CLI
• Windows 11 Home does NOT have Hyper-V — only Virtual Machine Platform + Windows Hypervisor Platform are available
• Cowork for Windows was released Feb 10, 2026 — this is a Day 1 issue
• Regular Chat mode works perfectly in the same app
• It's unclear if Cowork Windows officially supports Windows 11 Home or requires Pro/Enterprise for Hyper-V
• Would appreciate clarification on minimum Windows edition requirements

[ilask]

I had the same issue on Windows 11, and changing DNS solved it for me.

Symptoms:

• Chat worked
• Claude Code worked
• Only Cowork failed with “Cannot connect to Claude API from workspace”

What fixed it:

• Changed adapter DNS from local/ISP DNS to public DNS
  • Primary: 1.1.1.1
  • Secondary: 8.8.8.8
• Restarted Claude Desktop / Cowork VM

After this, Cowork started normally. This might be DNS path/resolution related.

[Amumuman]

I had the same issue on Windows 11, and changing DNS solved it for me.

Symptoms:

• Chat worked
• Claude Code worked
• Only Cowork failed with “Cannot connect to Claude API from workspace”

What fixed it:

• Changed adapter DNS from local/ISP DNS to public DNS

  • Primary: 1.1.1.1
  • Secondary: 8.8.8.8

• Restarted Claude Desktop / Cowork VM

After this, Cowork started normally. This might be DNS path/resolution related.

Thanks for sharing! I tried changing DNS to 1.1.1.1 / 8.8.8.8 but unfortunately it didn't resolve the issue on my end (Windows 11 Home, #24918). Still getting the same API connection error.

[Dadebr2]

I'm experiencing the same problem on Windows 11 Home. Cowork consistently fails to connect to the Claude API from workspace, while regular Chat mode works perfectly.

[GiulioRizzo82]

I experienced the same problem, but after a full restart of windows, it resolved that issue. Now i have another one: Impossibile avviare l'area di lavoro di Claude
VM service not running. The service failed to start.
Riavviare Claude o il computer a volte risolve il problema. Se persiste, puoi reinstallare l'area di lavoro o condividere i tuoi log di debug per aiutarci a migliorare.

[LeaAnneD]

Experiencing the same issue on Windows 11 Pro (not Home edition).
Environment:

OS: Windows 11 Pro, Version 24H2, Build 26100.7840
Claude Desktop: Latest version, downloaded Feb 11, 2026
Hyper-V: ✅ Enabled (all components checked)
Windows: Fully updated
Virtual Machine Platform: ✅ Enabled
Windows Hypervisor Platform: ✅ Enabled
VPN/Proxy: None
Firewall: Windows Defender - Claude allowed on both Private and Public networks

Symptoms:

Regular Chat mode works perfectly
Cowork shows: "Sorry, it's taking a while to connect to the Claude API... Taking longer than expected to reach the Claude API. Still trying..."
Eventually times out with: "Failed to start Claude's workspace - Can't reach the Claude API from Claude's workspace"
VM appears to start (gets past initialization) but cannot reach api.anthropic.com

Timeline:

Downloaded and installed Claude Desktop today (Feb 11, 2026)
Initially had Hyper-V disabled - enabled it and rebooted
Fully updated Windows
Issue persists after all troubleshooting

Notes:

This confirms the issue affects Windows 11 Pro users (with Hyper-V available and enabled), not just Home edition
The error message doesn't mention Hyper-V requirements, which could help users troubleshoot
This is a Day 1 Windows Cowork launch issue

[curtisalanhibbs]

I'm also experiencing this problem with Windows 11 Pro. Uninstalled Claude, enabled Hyper-V, rebooted, and reinstalled Claude. The problem persists.

[sanzhardanybayev]

Having the same issue as well

[christiandk00]

I also have the same issue today on Windows 11 Pro.

Tried to reinstall Windows 11 completely by doing a clean Install from a USB drivt (reinstall was planned anyway).
After reinstalling windows 11 pro, and downloading Claude desktop, i don't even see the Copilot tab anymore.

Note: Im now on a fresh windows 11 pro, only installed chrome, git for windows, Node and Claude Desktop. Chat and Code works, but the Copilot tab is not visible.