The file rundll32.exe is infected..... HELP!

I'm on a desktop w/XP which just got infected with a virus that has every imaginable executable file infected. I cannoteven open system restore or the internet. When I do click on Explorer any type in a webpage it just takes me to ANTIVIRUS SCAN website to but the software (yeah, like I believe that's legit!) Control panel will open but I can't do anything in it. McAfee ran a full scan but showed nothing. It is the only thing I could ven open, weird. Even WORD won't open. I have porn, viagra and other antivirus webpages opening up spontaneously, on their own even when I close EXPLORER. A pop up alert gives details, asks if I want to block the attack and I continuously click no because it takes me to "Antivirus" scan. I have had "rundll32.exe" is infected repeatedly. I would appreciate your help in helping me rid this computer of whatever problems are happening. Thanks!

• › [Solved] Trojan.ADH.2, Norton, WINXP vs WIN7, CD not seen in drive
• › How to remove youndoo if accidentally delete the files in C
• › thread exeption not handled black screen keeps comng up
• › threebg alias George Clooney sends zipped file virus infutur
• › [Solved] How to remove .scr virus without losing infected folders?
• › [Solved] Mozilla says unsecured connection for every website except a
• › [Solved] Chrome: Spinning blue wheel, slow page loads