Well, "not working" is kind of too general a description to really have any real idea of what might be causing you problems.
The most common complaint about the old trilogy is that often you might see distorted/ "psychedelic" colors, so maybe that's what you're talking about? If that's the case, then hitting alt-tab to your desktop and then switching back into the game a couple of times usually refreshes your graphics, and should clear it up.
Otherwise, you're going to have to be a bit more descriptive about what problems you're having for anyone to offer much of a solution.