Repost - PC freezes when opening certain torrent folders

I think I posted this in the wrong forum a few minutes ago ... here you go.

When opening a folder on my HD that has an avi movie, my computer does bizarre stuff. Usually the PC freezes, mouse and keyboard stop getting power, and the hard reset button doesn't work. A few minutes ago my cooling fans went on full blast, instead of the PC freezing. The time after that there was a constant high pitched beep coming from the tower in addition to the freeze.

Note: This only happens with a few torrent avi movies that I've downloaded, not all of them. Like 1 for every 10 movies.
Sometimes I can get the movie to play if I open it using a media player, clicking file, then open. But not on this file .. The.Road.2009.DVDSCR.XviD-ToXiC

I've done full virus scans and these files are clean.
Any ideas?