Revo Uninstaller -
http://www.revouninstaller.com/revo_uninstaller_free_download.htmlRevo Uninstaller allows you to not only uninstall unwanted software safely, but also enables you to remove those obnoxious residual files and registry settings that often remain afterwards.
CCleaner -
http://www.piriform.com/ccleanerThis program is awesome! CCleaner stands for Crap Cleaner and that's exactly what this software does - removes crap files that your computer simply doesn't need. A few tips:
1. Designate a directory where you can save a restore point and always choose to save one when you run this software - I save mine within the CCleaner directory.
2. When I perform the scan/remove operation that is in/under the "Cleaner - Windows" menu/tab, I tick all the boxes except the one labeled "Wipe Free Space". It's not that I am against wiping the free space on my hard drive, it's just that the operation takes freaking forever.
3. I also perform the scan operation in/under the "Cleaner - Applications" tab and I tick all the boxes before doing so.
4. I also perform the scan/delete operation in the "Registry" menu, ticking all the obxes.
I have been using both Revo Unistaller and CCleaner for years and have never had a problem with them messing up my computer. CCleaner is especially nice for tidying up a messy hard drive - which is often responsible for a slow computer.