On my old Windows XP with .75 GB RAM - adaware seemed to be churning down too hard on the resources - removed Adaware and it runs better. I kept malwarebytes and
Superantispyware. They have both helped to pull me out of situations with user's computers. From my experience I believe that Avast and Avira are two of the best AV programs. I currently use the Microsoft Security Essentials on one of my PC's - have heard it works pretty well - and should work well with Windows, but MS is a team so not sure it if would be better just because it was "made" by MS. Mr. Walen can choose what he wants, but I think he missed the boat on the Adaware over SuperAntiMalwre.
I have had problems with updating SuperAntimalware on a Windows 7 box, I no longer have - when I installed the full paid for version - not sure if that has been fixed, several people were having the problem at the time, perhaps a couple years back.