Oh!!
Looks like the Avira fan doesnt like it anymore. I was using AVG free some years back and felt the asame way before using Avast and then Norton.
And i did read some good reviews about BD, lets pray it is better than NAV.
And BD offers a free edition too.You cant get that on the downloads page, a bit tricky, but i got it.
Check it outCode:http://www.bitdefender.com/PRODUCT-14-en--BitDefender-Free-Edition.html