This tool has been around for a while, but I really wanted to take a minute to point out how great this tool is. CCleaner is a free tool for personal use and has served me well over the past few years. It is a small download, installs quickly, and can do a lot to clean up a messy Windows PC. The program can cleanup temporary files on your system from including Internet Explorer, Windows, and other programs. CCleaner does a great job at cleaning up your registry (but allow it to make a backup, just in case) and fixing issues with previously uninstalled programs. This tool can also be used to remove stubborn programs and delete pesky startup items that plague your system and hog memory. CCleaner is an all around great tool and, in addition to Virus/Spyware removal, should definitely be considered as one of your first steps to troubleshooting a slow running PC. You can read more about CCleaner and download the program for free here.