About Bit Defender-- I know this post is older, but I didn't see it until now.
I used to have BD - and it wouldn't let me play CoH! I had to jump through many hoops to get both to work, and even then, my system might crash - and I knew it was because of Bit Defender, as it was the only new software I had installed since the crashes began occurring at random.
I uninstalled it once I got Norton and haven't had a problem since.