dude.... that REALLY sucks... depending on what's got ahold of your machine there may not be much you can do.... if you're using XP, Vista or 7 you can try a system restore to the last time it saved restore point... you may also try installing spybot search and destroy and ad-aware, download and install them in SAFE MODE and see if what has your machine is some sort of spyware they can clean out for you, as a matter of fact this should be your first move.... if neither of those things fix it there may not be much else you can do with it..... I absolutely HATE when that happens and its the main reason why EVERYONE should be using software that acts as Anti-virus, Anti-spyware, pop-up stopper, firewall and identity protection all at once and all the time... Or, if you don't use ALOT of windows based software you can switch to Ubuntu it's pretty safe from Viri...... or, dual boot it and watch all your porn on it... lol in all seriousness though, I feel for ya.... it really sucks when your machine gets whacked....