Just to keep my computer maintained I downloaded AOL Computer Check Up. It's free from AOL and it takes about 2 minutes when I'm turning off the computer to clean the hard drive, cache, and all temporary internet files and cookies. This helps my computer run quicker and it also has a built in spyware/adware program in it to zap these things before they do any damage to you files. So all in all it works great and it's free!
I also use their Active Security Monitor each time I sign on, just to make sure my security systems are working. AOL is not my internet provider, but that's ok with them.