Brother's Profile is Infected

My brother's profile on the family computer has gotten infected, so I'm visiting for the weekend to fix it. I don't have any idea what he's done to get it screwed up, and I don't know if any other profiles are infected yet. Any who, onto the symptoms.

On start up, this pops up:http://img249.imageshack.us/img249/165/screen01i.th.jpg
I've never seen the HomeAntiVi... or pdinstall2009 icons before, and I suspect that they're part of the infection.

A short while later, this comes up:http://img249.imageshack.us/img249/6261/screen02o.th.jpg
I haven't clicked on Enable Protection yet because I don't know if this is also part of the infection.

When I opened up Firfox to upload these images, ths is the first page that opened up:http://img111.imageshack.us/img111/5749/screen03.th.jpg
While this page was open, the sound from some advertisement started playing. I can't remember what it was for though.

Since I'm only here for the weekend, a quick response would be greatly appreciated.

Edit: Sorry, I didn't see the read an run me first thread before posting. I'll go do that right now. I'll make another edit when I'm done with it.

 

Oh sorry, I went through the steps and it seems to have fixed the problem. Mods feel free to delete this waste of a thread.