So my old copy - with no fancy patches - could stretch the game to use my widescreen monitor. With this version i can't - what's up?

I have looked all over these forums with no help to be found. I don't understand the regedit stuff, i go in there and it has exactly the stuff it should need according to a widescreen guide, but it doesn't work - or at least i have no idea of how to get it to..