Off-switch

I think I've just found some sneaky bugger viruses on my machine. They're lurking in this file: C:\SWSETUP\HPGame\games which is full of stuff I DEFINTELY didn't download. Because I deleted my HP games ages back. And these long strings of numbers don't look very game like to me any way.

Thing is, my AVG didn't detect this. I was getting a bit suspicious when I got "No Threats Found" on multiple scans, because usually it at least picks up on internet cookies, right? Then I looked at it during a scan only to discover that it wasn't checking any files. Because it was stuck on THAT file.

So, now I'm stuck. how do I delete these things? They're slowing down my computer and making me nervous. I don't keep any kind of banking info on my computer, but I don't want to be a zombie spam bot either. And I *would* like to be able to check my credit card bill at some point without fear of these things yoinking my info.

I understand that the SWSETUP folder contains base software for the computer, so I really don't want to go removing things from there willy-nill and accidentally uninstall my operating system as a result.

Suggestions?