After sticking a good dozen old games on my new USB stick, I decide to run Outcast. It freezes up midway through the intro video, sticking my computer at a tiny resolution. I wait. My resolution goes back to normal, and AVG decides that "Intro" is a virus. It then says that it cannot find intro.
I get confused by this, and open my USB up. Except it is empty, and no longer under Computer.
The USB has been wiped clean, and reinserting it says the device has been inserted but does not bring it up under Computer, or give the option to install drivers in any of the usual places.

I'm running Windows Vista, and I have no idea in hell of what happened

EDIT: Okay, it turns out that the USB still works on another machine. The drivers just got wiped somehow.
Has anyone had a game from GoG be a virus, or a false positive?

You can't trust AVG, bro. Some games have filenames that resemble viral filenames, and some Anti-virus softwares are not programmed enough to tell the difference.