[BUG] Windows installation via irm ... | iex fails due to Cloudflare bot challenge

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?

The recommended Windows installation command from the official README:irm https://claude.ai/install.ps1 | iex does not work out-of-the-box. Instead of downloading and executing the PowerShell script, the endpoint returns a Cloudflare "Just a moment..." challenge page (HTTP 503 / managed challenge). This breaks the installation flow for all users who follow the current docs.

What Should Happen?

It should not trigger Cloudflare's CAPTCHA during installation.

Error Messages/Logs

irm https://claude.ai/install.ps1 | iex
Invoke-RestMethod: Just a moment...*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji"}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;padding-left:1.5rem;max-width:60rem}@media (width Enable JavaScript and cookies to continue(function(){window._cf_chl_opt = {cFPWv: 'g',cH: 'zd_Ejcx9DW1alwEN1PPCbq8JqSSc1sXFNFylmdUz9VY-1777646552-1.2.1.1-hXk5FGN_r.ffFR6YWgC1UltgtodWo24fm5bvIyLV7inYNPvMrRimvghao3ecmE4k',cITimeS: '1777646552',cN: 'SeynC8eCD6CMxru9VyGR3f',cRay: '9f4f8da82a428cac',cTplB: '0',cTplC:0,cTplO:0,cTplV:5,cType: 'managed',cUPMDTk:"/install.ps1?__cf_chl_tk=JVR80z7YtyF2ucgV_jfR3x0apyh.ajgrJ8j4Kj54DD0-1777646552-1.0.1.1-VQf_fImjAqNv5R.bktz.Cz4r..oxaDpeX8pLutLNjfQ",cvId: '3',cZone: 'claude.ai',fa:"/install.ps1?__cf_chl_f_tk=JVR80z7YtyF2ucgV_jfR3x0apyh.ajgrJ8j4Kj54DD0-1777646552-1.0.1.1-VQf_fImjAqNv5R.bktz.Cz4r..oxaDpeX8pLutLNjfQ",md: 'iwm3O1kbZcZcsbCYV_.2pnml58uwGbG6gCSc6E8y9Uc-1777646552-1.2.1.1-TOM5.nG36IoXadlOiDd35gRNXi1IUqZLeewSghd2R1OFAVyL8lJz9X2_zZzIz8bvTDtjgzux6qHga3aOyMTY24hI45MjbokJhuXa.7GcCoX3BRnf7Pvn1dCe1JjdIeNzEZMJWgaPvLC1VOMEwI0454KCV33a.llKJqGe31PoKeAHyJFr7ze8h50XReEOnl2wnaCZ9P1xVTppoHz4Aa9BEloCjb_m708t67DQaMfaGKmvruXcLbUnsHP0ZvRQUR9ud5Z.QwWO3_MZqV2JGskPCCT3NZsfC6j737iOkoTbBDeFuyLcef2LDHtboBBW90pFFnEvE0m.7aJsiTqPejfY7yTqrEh6dIk1CMgx1eazCI0L6eT1dHvyDTFGl2FEhMAqVusCTTdwofHY09QNp7sBMQDRyyBStEe1wgSgBVmlH9chDiotFP16M5PVmpcOOl1DGlHsQP28K265hlUdr00Peip6M75qvg68X5KspmsdhaPoCaP1X4jaLMG_Z4i2pvlXkrggu_8Q9GPNpwHRqhpW4oF9VKjX97f27AarD7xayKcWuGlSRG.MECt511C6auXI_mtE5eoDZUJmsizuayfDXSHA64tveFKl05BGJfjsLz2ISoG1viTWHh07qkRnxjdFGJCUqgeKfHSvPpk_hCULgj0bsJ6vJHNlbtYqcXjatDHu_.XPm47ZdfWSeEcpWEM09NY0mcC52LYfQ2lLbaFfm4bVgOKtT23gB3NLgxRLlS6Ut1qSQJl21qLekdz156ctQIK9lDHW73OE8_PeHRNiPoGltGfN0c5ZEBBSdqQaAjTC8KzuPgaEZjPir3DRJgqLtnuqMGg7.jQ5a9yBZFawbBBk89BzRBJKra8GlbHVSNXBtC6Y0Gjz49i7u1OLTWAveyGk6eAS.5CQtc8uz0721V5TMt_.smotlb5q_l7omHBJyIn5Q72dI8fYacE6b89rigt5vX56Wz1ABNS_Unoc5R2r134vBS5ezaCn3eXlHSB9HGNSUMox3kODl.lm_KR7',mdrd: 'NC3vb0hhQsfbywTto6tyZJgQazMhSXkrhU.UJdvy.WA-1777646552-1.2.1.1-_BB9i8ZncZZowEW6ZXXCr6DYJQZY7U2ZTfHhB2PdAaPi8S3pQzMNKVE4JoIkyv5QUUy0cUNBFjCy493oB_0NpTwsZerQtzk6ff.Tbc2yptx9jik3ThuRnozTR.CJWV7lT5DgI7rBZAirbHZIO2l7nZWku8HoBnD3nxnlzB6PlcIeECLAOaqpvl6H4vw9dWz2uh.LFN0DShtxN5ELyi1d5o_T5SCmqBKBhl.Bt5Ya1Mz.dgO_t6yXk_3dtbyk6yp2ptR5R0_nVY.5qo.ebCoSC5utnb2UaivMJ27fReQZf64NI.A9E50O6twbUK2P98On',};var a = document.createElement('script');a.nonce = 'SeynC8eCD6CMxru9VyGR3f';a.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9f4f8da82a428cac';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null,"/install.ps1?__cf_chl_rt_tk=JVR80z7YtyF2ucgV_jfR3x0apyh.ajgrJ8j4Kj54DD0-1777646552-1.0.1.1-VQf_fImjAqNv5R.bktz.Cz4r..oxaDpeX8pLutLNjfQ"+ window._cf_chl_opt.cOgUHash);a.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(a);}());

Steps to Reproduce

1.Open PowerShell on Windows.

2.Run: irm https://claude.ai/install.ps1 | iex

3.Observe the output and error.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.126 (Claude Code

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_