bitdefender sucks!! don't use it. They are being sold for RM49 or something right now to get people to buy them but they are ineffective in getting rid of malwares.

My friend's PC using bitdefender but got all sorts of virus problem. Then switched to avg, better but keep on prompting got virus and all but then switched to avira anti-vir. No more problems. Best of all avira is free.

But if you want good and stable antivirus, try nod32. It's quite effective (not 100%) but light on memory. Problem is, not so easy to learn how to use.