A couple of days ago, my little brother told me that he thought he'd got a Virus from MSN Messenger, and could I check and see if I could get rid of it?
I checked, ahnd found that for some reason the AVG hadn't been running when it was meant to. I've fixed that, and found that I had gogo.exe. I also ran SpyBot, and that fould a plethora of things, including Smitfraud.C-Toolbar888.
After several attempts to get rid of it, I came here to ask for help. Now, I've run the AVG Anti-Spyware program which uncovered 532 threats, including Hupigon and a couple of othgers that were serious threats. While I followed your advice, it seemed to be determined to delete them and also told me, in the report, that it had found absolutely nothing.

I've included the report.
I've also run the Super Anti-Spyware, and that prodiced a log that I have saved, and also run HiJackThis.
The problems I've noticed are that an Internet Explorer window will open at random, often to a casino site or other advertising, including one for a site called Amaena (I think). The compuyter has also been slowing RIGHT down, which is standard for an infection. AVG has been popping up and warning me of threats every so often.
Anyway, I'm giving you the logs, and hopefully, you'll be able to help me get rid of whatever nasties that have been crawling about in my machine.
Thanks for your help.