I had firefox open, with tabs open for youtube wikipedia and a torrent site. My firefox suddenly closed and a BitDefender pop up came up saying that a virus had been blocked, but that was before I downloaded anything. I opened firefox again, and it opened up the 3 tabs I had open before, but the Bit Defender pop up didn't come up again. Then I virus scanned and BitDefender said I had 2 infected files but that they had been deleted. Does that just mean my computer is safe again? How do I make sure that my computer is safe?