CCleaner is one of the best combo Windows registry, temp file and privacy cleaning tools out there that I have ever used.    I have been using it for year to safely clean my registry and speed up my computer.    It’s one of the first tools I use when cleaning up a slow computer.   It also has a built in tools for editing your startup files, removing old programs and managing your systems restore files.  I use it on my computers at least one a month to keep them nice and tidy and running smoothly.    Spyware and adware free, you do have the option to install the Yahoo toolbar during the installation process but it’s not need to use CCleaner.   It also has a neat feature where when you right click on your trash can you have the options to run it or open it!   Works on all version of windows starting with 3.1 all the way to windows 7.     The newest release is optimized for windows 7 also.   http://www.ccleaner.com/