I just recently purchased BitDefender Internet Security 2008. I had a program I was going to install that was downloaded from the internet. It didn't come from a reputable source and I suspected it may contain a virus. So I scanned it with BitDefender and it said it was clean. So I installed it. Couple of days later my system was becoming unstable so I suspected what I had downloaded had a virus and BitDefender missed it. I did a complete system scan with BitDefender and sure enough I had 9 viruses that weren't there before I installed the program. BitDefender said it was unable to remove the viruses. So I ended up downloading a demo of AVG antivirus and ran a scan with it and it found the 9 viruses and was able to remove all of them. I scanned the file that had originally infected my system and BitDefender said it was clean. Scanned it with AVG and sure enough it contained 9 viruses (trojans, etc). Why would BitDefender not pick up on this and also not be able to disinfect my system? I'm pretty dissapointed with BitDefender I should have purchased AVG. By the way both programs were up to date with the latest definitions.