I think this has been asked before but I got a virus or something that makes my background on the main page say : Warning! Spyware Detected on your Computer! Install an antivirus or spyware remover to clean your computer. View the list of top spyware removers(link)
My dad's computer had that screen a few weeks ago. What i did was ran system restore and restored to a previous date. Then I ran avg virus scan, adaware, and spybot search and destroy. I deleted all the crap it found, and now the computer is back to normal.
That is propably SpyAxe/Smitfraud. Please post your HjT-log. Instructions -> http://forums.afterdawn.com/thread_view.cfm/263784 (steps 3 and 4)
theres been alot of that spyware smitfraud recently,you should all have real time protection with anti spyware program to avoid this crap. send in a HJT log to see whitch one it is, your probaly going to have to download smitrem and run that, spertti is the one to ask for this one.