[BUG] Claude Desktop installer fails on Windows Canary 26200 + AtlasOS: 0x80073CF9 MSIX failure, ghost PackageFamily in StateRepository, --no-cowork serves ARM64 on x64

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?

Every install attempt fails instantly with HRESULT 0x80073CF9 / inner error 0x80070490 ("Failure in the Evaluated state handler"). The StateRepository-Machine.srd SQLite database contains a PackageFamily row for Claude_pzs8sxrjxfjjc with no corresponding Package entry. Windows treats every fresh install as an update-over-missing-files and rejects it immediately. Event ID 472 in AppXDeploymentServer confirms Windows tries to move a package folder that doesn't exist (0x80070002) on every attempt.

Verified via direct SQLite query:
SELECT * FROM PackageFamily WHERE PackageFamilyName LIKE '%Claude%';
-- Returns row ID 154: Claude_pzs8sxrjxfjjc

SELECT * FROM Package WHERE PackageFullName LIKE '%Claude%';
-- Returns nothing

No Claude files exist on disk in WindowsApps or Deleted. All MSIX services running (AppXSvc, StateRepository, ClipSVC). All dependencies present (WindowsAppRuntime 1.2-1.8, VCLibs, UI.Xaml). No blocking policies found.

What Should Happen?

Claude Desktop installs successfully on Windows Canary 26200.

Error Messages/Logs

AddPackage fails instantly (~250ms) every time with HRESULT 0x80073CF9. The installer never gets past the "Evaluated state handler" check. The error dialog that should offer "install without Cowork" does not appear.

Relevant log excerpt:
Installing via AddPackage (current-user)...
MSIX installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CF9
ERROR dialog (with log path): Administrator access is required to install Claude with full features. You can try again or install without Cowork.

Steps to Reproduce

1. Install Claude Desktop on Windows Canary build 26200 with AtlasOS debloat applied
2. Install fails, leaving a ghost PackageFamily entry in StateRepository with no corresponding Package
3. Every subsequent install attempt fails identically with 0x80073CF9
4. Rebooting, clearing temp files, removing AppxPackage, deleting WindowsApps folders, and manually replacing StateRepository-Machine.srd all fail to resolve it

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A - This bug is with the Claude Desktop installer (ClaudeSetup.exe), not Claude Code CLI. Unable to install Claude Desktop to obtain a version.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• OS: Windows 10.0.26200 (Insider Canary channel)
• Debloat: AtlasOS applied
• Architecture: x64 (AMD Ryzen 7800X3D)
• Claude installer version: 1.1.8629
• SHA256: 1d0e38aaf371de09f4102d1f9504cdde4c314247b07aa3f068e17f573be1f16e
• All MSIX services running: AppXSvc, StateRepository, ClipSVC, AppReadiness
• Sideloading: enabled
• S Mode: false
• Developer Mode: not required (sideloading already enabled)