App Compatibility Cache
Windows stores application compatibility analysis data under %WinDir%\AppCompat\Programs to support Program Compatibility Assistant, installer detection, and shim matching for executables the system has seen before. This cache can include compatibility inventory databases, executable matching records, and generated lookup data used to decide whether an app needs legacy fixes, elevation prompts, or compatibility layers. Kudu removes these cached AppCompat program records so Windows can rebuild fresh detection data without touching installed apps, user files, accounts, or settings.
Why clean App Compatibility Cache?
- Stale executable matching records can make Windows keep applying the wrong compatibility shim after an app update, which shows up as odd scaling, forced admin prompts, or a program insisting it needs an older Windows version
- Outdated Program Compatibility Assistant data can cause repeated compatibility warnings for software that already runs correctly, so users keep seeing pop-ups after launch or install
- Cached installer-detection results may misclassify a normal executable as setup software, leading to unnecessary UAC prompts or altered launch behavior that did not happen before
- Old AppCompat inventory entries can survive after software is replaced with a newer build in the same folder, causing launch failures or immediate closes until Windows re-evaluates the executable
- Corrupted compatibility cache files can delay first launch while Windows retries detection logic, which users notice as a long pause before an app window appears
- Machines with years of accumulated AppCompat program records can carry forward bad compatibility decisions from previous versions, producing inconsistent behavior between identical systems until the cache is rebuilt
Cache paths Kudu targets
Windows
%WinDir%/AppCompat/Programs |
Common questions about App Compatibility Cache
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Available on Windows, macOS, and Linux. No account required, no feature gates, no telemetry without consent. All cleaning targets are open source and community-auditable.