Dear daxrod,
You need a combo to keep your pc purring along nicely. Though a bundled security suite is the norm these days (even i have KIS2009), a dedicated A-V, one Antimalware, one or two(better) Anti-spyware and a well configured Firewall is "ideal".
1) An Anti-Virus in realtime (ProActive) for free is a boon and Avira Antivir free has that,
so go for it. An additional bonus is you have an anti-spyware incorporated in it.
2) MBAM (free),
3) SAS (free), and
4) Install Comodo Internet Security Suite, and disable the anti virus function and Enable the Firewall (Kindly read the Firewall Help manual),because without your input it's as good as a dodo!
5) I have the free version of "a-squared" (website :
http://www.emsisoft.com/en/software/free/installed and despite the false-positives, it gives you the path(Vital) as to where the infection is(supposedly) lurking and using that you can submit the file to virus total(Website :
http://www.virustotal.com/ ).
6)SpywareBlaster with Spyware Guard have a new Avatar and you can add it to your arsenal against spyware.
Best wishes.


PS: Install them(if you wish) one after another.That's a safe policy in my personal opinion.