I got a virus...

[BK1248]

I keep getting a pop-up that says "ur computer might be infected with trojan.zlob and it says i should download idefender.exe. "

But when i use the norton screeing test nothing appears. Do i have to get a spyware detector? i try to do a system restore but it says i havent changed my computer in the last few months. I dont need much on my computer except PT and StatKing for the live play. what should i do? i dont know much about computers.

ty

edit: I changed your title. I friggin' hate that "ur" stuff. Plus no rewards in CTH, but mostly I hate that that "ur" stuff.