[BUG] Claude Desktop installation fails with HRESULT 0x80073CFF on Windows 11 Home

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?

Claude Desktop installation fails at the MSIX AddPackage step with HRESULT 0x80073CFF. This occurs on a fresh install attempt.

What Should Happen?

Claude Desktop should install successfully on Windows 11 Home without errors.

Error Messages/Logs

Installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CFF

Steps to Reproduce

2026/07/19 17:35:22.758803 Standard install (not split-account), using AddPackage
2026/07/19 17:35:22.758803 Installing via AddPackage (current-user)...
2026/07/19 17:35:23.557495 MSIX installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CFF
2026/07/19 17:35:45.346091 Elevated process exited with code 1
2026/07/19 17:35:45.346091 Elevation failed: elevated installer exited with code 1

ClaudeSetup.log

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

N/A - Desktop app installer bug, not Claude Code

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Note: This is a Claude Desktop installer bug, not a Claude Code issue. Filing here as there is no dedicated Desktop app issue tracker.