If AdAware didn't work for you (I've never had a problem, I love it), you should go to
www.download.com and search for "Spybot Search and Destroy" it's like AdAware in that it removes spyware and such, but it's not AdAware so it shouldn't fuck your computer up. I'd also guess that it wasn't AdAware that fucked up the computer, but a piece of spyware that REALLY didn't want to be deleted and lashed out in an attempt to save it's life.
Using AVG is good too. If you have a couple floppies around, I'd use the AVG program to make an emergency floppy set, then boot with those and let it scan for viruses that way. Some viruses arn't removed properly by AVG unless you use the emergency floppy disk set (why?!! I don't know). Also, don't forget to update your virus definition files every once in a while (once a week, since you're on broadband).
Of course you could just get a Macintosh and not have to worry about viruses and trojins.
*me ducks*