If Claude Desktop on Windows just started throwing "This app can't open" out of nowhere, and reinstalling either doesn't fix it or fixes it for exactly one session before it breaks again - you're not imagining it, and it's not your machine. It's a real, documented Anthropic bug, and the standard "just reinstall" advice actively makes the underlying problem worse if you're using Claude Code, because it can silently destroy your session history in the process.
The actual root cause
Recent Claude Desktop builds on Windows ship as MSIX packages (Microsoft Store-style installers), and they bundle vk_swiftshader.dll. On any machine with Memory Integrity (HVCI) turned on - which is on by default on a lot of newer Windows installs - Windows Code Integrity blocks that DLL outright (you'll see event 3033 in the Event Viewer if you check). The GPU process crashes, and the whole MSIX package gets flagged Modified, NeedsRemediation by Windows' own package system. The next launch fails with "This app can't open."
Repairing or reinstalling only resets the clock - the same package self-corrupts again within a session, because the underlying trigger (HVCI blocking that DLL) is still there. It's been independently reproduced on NVIDIA, AMD, Intel-integrated, and Windows-on-ARM machines, and it's tracked in Anthropic's own bug tracker: anthropics/claude-code#88323.
Why "just reinstall" is actually risky if you use Claude Code
Reinstalling can silently destroy Claude Code's chat history while everything else (regular Chat, project files, memory) survives intact - a separate, confirmed bug: anthropics/claude-code#62997. Worse, the lost sessions are often unrecoverable from the UI even though the transcript files are still sitting on disk, so you frequently can't even tell what you lost without checking the filesystem directly: anthropics/claude-code#81907.
The fix that actually sticks
The permanent fix isn't repairing the MSIX build - it's switching to the older, non-MSIX Squirrel build, which has no package-integrity status for Code Integrity to flag in the first place. Short version:
- Get the current version from
https://downloads.claude.ai/releases/win32/x64/RELEASES, then build the download URL yourself (AnthropicClaude-<version>-full.nupkg) - the version number changes, so a hardcoded URL 404s. -
.nupkgis a zip file wearing a different extension. Rename it to.zipand extract normally. - Copy everything inside
lib\net45\(not the folder itself) into%LOCALAPPDATA%\AnthropicClaude\app-<version>\. - Make a Desktop shortcut to
claude.exein that new folder. - Fully quit the old MSIX build first (tray icon → Quit, or Task Manager) - Electron's single-instance lock means a still-running old build silently hijacks the new one's launch.
- Uninstall the old MSIX package for real once the new one's confirmed working, so Windows doesn't keep quietly auto-updating it back over your fix.
Full step-by-step with every gotcha I actually hit (nupkg extraction, the single-instance-lock trap, when it's safe to delete the download folder) is in the repo linked below.
Before you touch any of this, check if you're actually at risk
Not everyone on HVCI-enabled Windows is broken yet - some machines just haven't hit the trigger. I built a free, zero-setup diagnostic script called ClaudeGuard after this happened to me for real: it checks your package status, Code Integrity event log, and Memory Integrity state (read-only, changes nothing), and separately backs up your ~/.claude data with a manifest so if you do reinstall, you have a real answer to "did I lose anything" instead of guessing. Single PowerShell script, no dependencies, no account, no cost.
If you're already comfortable with git/bash/jq and want comprehensive cross-machine backup of Claude Code's entire data model, jtklinger/claude-code-backup-guide does that well and is actively maintained - ClaudeGuard is narrower on purpose, built specifically for the Windows MSIX corruption itself, not as a general backup workflow.
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