You should read yesterday's article about cleaning crap files from your PC.
Staying in the same topic, I want to share with you my secret on the best way to uninstall an app from Windows 7 or Windows 8. Sure you could use the built in Add / Remove program option of the Operating System but that never seems to get everything off. After running the default uninstaller, there always seems to be garbage left behind.
This is why I love the free version of Revo Uninstaller. Revo Uninstaller finds and removes the extra files Windows mayhave left before. For me, this has become a go to app and I never use the Windows add/remove programs.
Revo also has a couple of extra built in functions you may find interesting. My favorite is a feature called hunter mode for programs with hidden uninstallers. In hunter mode, you drag a bulls-eye to the app icon and it tries to find the best way to remove it.
Don't buy the Pro version! The free regular version is what you need. Here is a direct link to download the free version.