got TV out on your video card? I watch all my movies this way. I have 5.1 sound but i used to output the sound to a 5.1 capable hifi and used that for dvds and such. Coupla ways to do what you want, depends on what stuff you have to hand really
KiSS make a divx player if thats the sorta thing your after,(
Ebay). For that money money though you might as well get a new video card with a tv out and rig the sound