There is a brutal rootkit going around, I've seen 3 people infected with it in the last week. Are you getting popups from "Windows 7 Security 2012" which is asking you to pay $59.95 for a year of protection from viruses? This "countermeasure" itself IS the infection. Oftentimes these will hijack your entire browser and not allow you to do much else except buy their product. A few options, use "RKill" to kill any unknown .exe's use "Hijack This!" to kill any unknown startup entries (you can remove legitimate entries too, so be conservative) Use system recovery to rollback to preinfection period. Please report back.