I was looking at some Anti virus software reviews and I guess Bit Defender is the best and most used one of last year. Windows Defender scored a 2.0 out of 8.0 in a comparison against a few others.I have had no issues with Windows Defender to speak of and as Windows 8 gets more mature; Defender get's more tuned IMO. So I noticed it is a bit more aggressive now that last summer. I understands that it lacks in features compared to it's 3rd party application counterparts but it seems to be effective for Home use. So why is Bit Defender orders of magnitude better according to some sites I briefly looked at?