Perfect Companion is a system utility that will help you maintain the integrity of your Registry. It's especially useful for PCs that have lots of software installed and uninstalled, as it cleans up the garbage left by many uninstallers. Registry scans are thorough and time-consuming, and revolve around finding and removing invalid keys, and making sure that .dll and .ocx files are properly registered. An undo file is created that allows you to easily reverse the changes if a problem arises from any of the modifications. Perfect Companion also allows you to browse and remove items that are tagged to load with Windows startup. Finally, a SnapShot feature allows you to scan the file content your Windows folder, C drive, or all available hard drives. Subsequent scans, which report any and all differences found, can be easily saved to disk. All in all, Perfect Companion is a fine housekeeping utility. If your computer sees a lot of new software installs/uninstalls, you should really give it a look.