Wow, that news is frightening and good all at the same time. It's good that you now have these tools and have cleaned up some of the viruses, it's also bad because after 200 viruses found on you're computer I have to suggest a reformat and reinstall. IMHO, there is no good reason to press forward after that sort of damage. I assume there has been, at the very least, some damage done!
At any rate, always keep your AVG running and updated. That goes for Adaware and Spybot Search and Destory too.
You need a good Anti-Trojan program because it's pretty vital to know whether or not a kiddie/hacker has control of your machine.
Again, I recommend doing a reformat and reinstall in this particular case. And kid, please, for the sake of computers worldwide, set yourself up a
limited account, as to avoid this sort of garbage in the future. In short, a limited account will not give viruses and trojans the permissions they need to execute themselves on your computer.
If your not up to doing a reinstall, just keep running your Virus/Trojan scans regularly. Remember, only download from trusted sites, ie downloads.com zdnet.com webattack.com etc...
Take care bro..
BIG"B's Linked Online Security FOR XP This has been another big b production