Did you make sure your desktop color depth was set to 16-bit color before you started Unreal with the 3dfx glide drivers? Some games just won't run when your desktop color depth is at something higher than 16-bit (my games Half-life, Q3Test, and Descent Freespace won't run or would crash unless I didn't switch to 16-bit color while in Quake II, I don't need to switch color depths, go fig). Hope this helps.
[This message has been edited by agent374 (edited 08-24-99).]
What version from the cd is unreal ? The 2.25 patch doesnt work with All versions so check it out on the Unreal website.
Also uninstall the game, then resinstall. When the game asks you if you have a 3d card say yes, then quit the game dont play it or select Do You Want to Use it. Run the appropriate patch then everything should be fine.