co worker of mine had gotten a nastie on his machine while searching the better porn sites, so he says...
..he tried to "fix" the problem using some on line !@#$ that just compounded the problem..
..got his system back up and running, got rid of bad stuff, installed and taught him how to use SpyBot, AdAware, SpyWare Blaster, HiJackthis, Zone Alarm and his AV (Symantec) programs...
while he tried to fix computer, he erased/deleted notepad.exe..don't know how he did it or where it went....

Machine is:HP/ Win xp...can get more info if needed.