hmm ... does your IE work at all???

if it does u might want to try running a online virusscan http://housecall.trendmicro.com/

but yeah ... sounds like there might be a process running in the background that seems to be corrupting everthing ... u might want to try ctrl+alt+del and look at the processes list... and terminiate all the ones that arent usually there that seem kind of suspicious...

... hmm... if i could chat with you on msn or irc it would be easier to talk u thru this...

but basically, theres probably something not supposed to be running, u need to terminate it, then remove it (like run a virus scan and/or spyware scan)