It always helps to tell a little bit about the peripherals that are in the machine when you have a problem, but there's a couple of things to remember:
2. if your machine has a TGA2 in it, it won't run X; if it has a Trio64 in it, you may need to add:
In any case, use tip #1 should allow you to get a complete install, and then you can play around getting X configured.