[BUG] Claude Code installer hangs indefinitely at "Setting up Claude Code..." on Windows Server 2019 — process spins CPU with no network activity
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?
Hi,
I'm hitting a reproducible hang during Claude Code installation/setup on Windows Server 2019 Standard. Details below.
Environment:
OS: Windows Server 2019 Standard, build 17763.8511 (updated from 17763.6640 — same behavior on both)
PowerShell: 5.1 (build 17763)
Claude Code version: 2.1.226 (win32-x64)
Install method: native installer (irm https://claude.ai/install.ps1 | iex)
Symptom:
The installer downloads successfully (confirmed via -Verbose: manifest.json and claude.exe, 287053472 bytes, both download fully and cleanly). After that, it prints "Setting up Claude Code..." and hangs indefinitely — I've let it run 10+ minutes with no progress or completion.
Diagnostics already performed:
Get-Process shows the claude-2.1.226-win32-x64 process actively consuming CPU (CPU time climbed from 268s to 334s between two ~30s-apart samples — roughly saturating a full core continuously)
WorkingSet memory is flat between samples (not growing) — suggests a spin loop rather than active work
netstat -ano for the process PID shows zero active connections during the hang — so this isn't a network stall
Ruled out network/TLS causes: forced TLS 1.2 explicitly, no proxy configured, verified real certs (Google Trust Services / Let's Encrypt) after excluding Anthropic domains from local ESET SSL inspection — no change in behavior
No SmartScreen prompt, no AV detections logged in ESET
This also affects claude.ai's /web-setup flow, which requires the same CLI setup step to complete
This looks like an infinite loop or deadlock specific to the setup/post-install step on Windows Server 2019, not a download or network issue. Happy to run Process Monitor / Process Explorer with a thread stack trace if that would help you diagnose the specific hang point — let me know what would be most useful to collect.
PS. No any restrictive policies. Anti-virus software fully disabled. AppLocker active, but have no rules. Claude Desktop intalled and works fine. It says:
Here is the current diagnostic summary: AppLocker is empty, WDAC is disabled, there are no blocking events, the antivirus isn't logging any threats, and the network is clean (TLS is fine, and there are no connections at all during the hang). Yet the process is actively consuming CPU without a corresponding increase in memory usage—this strongly points to a bug in the Claude Code setup-phase code itself, manifesting specifically in the Windows Server 2019 environment, rather than an issue with your system configuration that could be "resolved" via policies.
What Should Happen?
Claude Code should be installed
Error Messages/Logs
No any errors in logs. Only "Setting up Claude Code..." in PowerShell.Steps to Reproduce
Don't know. May be just Windows Server 2019 required for reporoducing this bug.
Claude Model
None
Is this a regression?
I don't know
Last Working Version
_No response_
Claude Code Version
likely 2.1.234 (as installer named: claude-2.1.234-win32-x64.exe)
Platform
Anthropic API
Operating System
Windows
Terminal/Shell
PowerShell
Additional Information
The same behaviour with "Windows Terminal"