Claude Code Installation Troubleshooting on Windows

If you’ve tried to install Claude Code on Windows and hit a wall — permission errors, PATH problems, PowerShell execution-policy blocks, antivirus interference, corporate proxy timeouts, or the dreaded “claude: command not found” after a successful install — this free guide is the diagnostic and repair manual. It walks every common failure point with the exact PowerShell commands to diagnose and fix each one, plus a 30-minute systematic recovery recipe that gets you from “nothing works” to a clean working install regardless of which specific thing went wrong.

Written for the developer setting up Claude Code for the first time, the engineer rebuilding a machine after a hard drive replacement, the team lead getting a new hire’s laptop online, and the IT support technician helping someone else’s install. No assumptions about prior Linux experience — every step is Windows-specific and explained with the actual commands to run. By the end you’ll have either a working Claude Code install on Windows or a confident diagnosis of why your machine specifically needs the WSL2 fallback path (also covered).

The guide is honest about what works in 2026 and what does not. Some Windows machines — particularly managed corporate machines with locked-down execution policies and aggressive endpoint security — fight the native install at every step. Other Windows machines install cleanly in five minutes. This guide tells you which one you’re on and what to do about it. Every command in the guide has been tested across Windows 10 and Windows 11 with PowerShell 5.1 and PowerShell 7.

What This Guide Covers

• Why Windows installs hit more friction than macOS or Linux — and the predictable failure modes
• System requirements and the pre-install sanity checks that prevent 80% of failures
• The standard npm install -g @anthropic-ai/claude-code command and the five places it commonly breaks
• Node.js and npm errors during install: EACCES, ENOTFOUND, EBUSY, EPERM, deprecation noise, native-build failures
• PATH and environment variable problems — User vs System scope, VS Code terminal gotchas, the where node trick
• PowerShell execution policy errors and the safe RemoteSigned fix
• WSL2 vs native Windows install — when to pick each path with honest trade-offs
• Antivirus, firewall, and corporate proxy issues — including NTLM proxy authentication workarounds
• Login, API key, and authentication failures — including localhost callback issues and stale token cleanup
• Verifying the install with an end-to-end test session
• Upgrading, reinstalling, and the nuclear-reset clean uninstall recipe
• The 30-minute systematic recovery recipe — seven steps that get any Windows machine to a working install
• Frequently asked questions: admin requirements, cmd vs PowerShell, multi-machine installs, blocked-domain workarounds

This guide is free. No signup, no email required. AI Learning Guides publishes free troubleshooting eguides for the most common AI platform and developer-tool installation issues because the working pattern is roughly the same regardless of which tool you’re installing, and saving you an afternoon of debugging is a useful thing to do whether or not you ever buy one of our paid guides.