Need help with downloading OpenGL for SIS 630/730, PC chip

If anyone can help I would sure appreciate it. I’m trying to play the game Medal of Honor and it keeps coming up telling me I need a video card that is multifunctional or something and saying it cannot find OPENGL. I called the people where I got my system WIN 98SE and they assured me that my video card should be universal, and THOUGHT it had OpenGL but not sure. I have a PC chip and they said I could try updating my drivers which is SIS 630/730. This is all greek to me. I’ve went to the SIS homepage and haven’t had much luck. Please help! Thanks, Darla