I"m trying to help my mother get her desktop computer working like new. Basically, she would download a bunch of crap and would never ever even turn off her computer for months and maybe even years at a time. I had a buddy come over who knows computers but he overcharged and I don't know if I got done really what I wanted. I thought the computer might need a new fan because before my mom stopped using this computer there was a very loud rattling which I thought was the fan. My buddy took the case off and cleaned it although there is still a bunch of dust and it's not that loud like it used to be. Maybe it was because mom never turned it off. ANyways, I would like to get this computer cleaned of unneeded programs, spyware/adware/virus protected, and just running as clean and fast as it can because she bought this brand new for a lot of money. Also, what is the best way to physically clean out the inside of the computer? I would appreciate help and will follow instructions.