I edited this post from earlier if anyone is wondering. . .
Two downloads that will allow you to play almost anything on the PC. FFDshow
: Just install and forget. Once installed it will run whenever you try to play an otherwise unrecognized format. If you like to tinker there's plenty of room for that. VLC media player
. This player is still a little quirky, but for our purposes here, it does the job nicely and it's not a resource hog like WMP and QT on Windows.