Where Is the Windows Installer Cache?
Windows Installer folder with cached .msi and .msp files needed for uninstalls and patching.
Last updated
Windows caches installer packages as stripped .msi and .msp files directly under C:\Windows\Installer. Uninstalls, repairs and updates all draw from this cache.
Deleting it breaks uninstallers with missing source errors. Patch management tools can reclaim orphans, but hand deletion is permanent damage.
Where Windows stores this, by platform
C:\Windows\Installer
Needs admin; files use random hex names by design. Never delete by hand. Use patch cleaner utilities that verify orphans first.
Frequently asked questions
Uninstall fails asking for an .msi file. What happened?
Its cached installer is gone from this folder. Re download the same version installer and point the dialog at it.
How do I safely shrink the Installer folder?
Use a cleaner that moves verified orphans to external storage first. Keep the move reversible for a month before deleting.
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