[BUG] Claude Desktop arm64 installer silently fails on Surface Pro 11 (Snapdragon X, Windows 11 Build 26200) — no log written, no error dialog

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?

Running Claude Setup.exe (arm64, 151MB) on a Surface Pro 11 with Snapdragon X ARM64 processor results in completely silent failure. The "Installing Claude" splash screen appears briefly then disappears. No error dialog is shown, no log file is created at %LOCALAPPDATA%\Temp\ClaudeSetup.log, and no MSIX package is registered. Running as Administrator produces identical silent failure.

What Should Happen?

Claude Desktop should install successfully, or at minimum fail with an error dialog and write a log file to %LOCALAPPDATA%\Temp\ClaudeSetup.log

Error Messages/Logs

No log file is created. Confirmed via:
Get-Content "$env:LOCALAPPDATA\Temp\ClaudeSetup.log"
→ Cannot find path — does not exist

Get-AppxPackage -Name "*Claude*"
→ Returns empty (no package registered)

Installer file confirmed arm64: 151,466,656 bytes
Registry keys confirmed set (AllowAllTrustedApps=1, AllowDevelopmentWithoutDevLicense=1)
Developer Mode: ON
No prior Claude installation (AnthropicClaude folder deleted, AppxPackage absent)

Steps to Reproduce

1. Device: Surface Pro 11, Snapdragon X ARM64, Windows 11 Build 26200.7840
2. Enable Developer Mode (Settings → System → For Developers)
3. Set registry sideloading keys via admin CMD:

reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock" /t REG_DWORD /f /v AllowAllTrustedApps /d 1
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock" /t REG_DWORD /f /v AllowDevelopmentWithoutDevLicense /d 1

1. Reboot
2. Confirm clean state: Get-AppxPackage -Name "Claude" → empty
3. Download Claude Setup.exe (arm64) from claude.ai/download (151MB)
4. Run: Start-Process "Claude Setup.exe" -Verb RunAs -Wait
5. Observe: splash screen appears briefly, disappears silently. No error, no log.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

Never worked

Claude Code Version

N/A — this is the Claude Desktop installer, not Claude Code CLI

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

This appears specific to ARM64 architecture. Unlike the x64 failures documented in #25162, #25194, #25385 (which at least write logs and show errors), the arm64 installer crashes before initializing its logging subsystem entirely.

Related issues: #25162, #25194, #25385, #25914, #28231