Or stick to TRSDOS 6.2 - no one writes virus code for that
This would make sense, since I have Spybot on my machine. Honestly though I haven't used it (actively) for quite awhile, so I don't know how necessary it is. I don't know if my AVG (free edition) is enough on its own. As low as my CPU usage is, I guess it's not hurting anything by having it. I keep my AVG up to date, but I haven't updated Spybot in a long time - probably should!
I switched from AVG to Avira a while back. Had heard too many things about AVG just becoming more and more bloated and taking up unnecessary resources from my IT friends. Either one seems good, just a matter of personal preference I guess...
I don't actively run a malaware scanner constantly, more like an monthly tune-up. Usually run them the same time I run CCleaner to tune up my registry and clean junk files left behind after uninstalls and such.
FWIW, I did find my problem and correct it. It was just a several days after this fell off the front page so I didn't want to bump it back up.
My probably was that a couple weeks ago when downloading an Adobe flash update for Firefox it also automatically downloads a Mcafee AV program. It did not tell me that it downloaded it. But it turns out that McAfee and Symantec were "fighting each other" and killing my CPU usage.