I think I had to do System Restore the last time I got a big virus. That was horrible because I tried installing Malware Bytes but the program still wouldn't work or whatever. It was strange.
Those false antivirus programs usually come from shady porn sites.
That's not entirely true. A fake antivirus popped out my tab when I clicked a song link on 4shared to listen to a song. I thought it was strange so I clicked it again and the same thing happened. A few months later, it happened again, but it didn't harm my computer. It just kept me from closing the tab until I clicked on it. I didn't do either. I just ended the browser window and it was fine. Sentinel, just keep from downloading sites for a while until you get that antivirus.