I'm in agreement with the current majority vote; NOD32.. reliable, and has no affect on system performance. I was an AVG fan until I tried NOD32. Whoa, what a difference.

Re: effective antivirus Not Free: My favorite scanner, because it's reliable, extremely fast and does not consume all your system resources (even if you're scannnig network folders and email) is...

You could try 3rd party software like #-Link-Snipped-# to backup and restore those settings. They got a new version coming out soon, but costs money. Best regards