When applications are installed and updated on the Windows Operating System a hidden directory c:\Windows\Installer is used to store the installer (.msi) files and the patch (.msp) files. Over time as your computer is patched and patched again, these installer files become outdated and orphaned. They are no longer required, but they can take up many gigabytes of data.
PatchCleaner identifies these redundant/orphaned files and allows you to either (Recommended) Move them to another location. If you want to play it safe, just move them to another location, and if things start going wrong you can always copy them back or Delete them.
