Well, the program runs fine on my computer, running on an ATI graphics card. There is something you can try, called
GLDirect, that basically converts the opengl draw commands to directx, which may allow you to see what's going on. Basically:
1) Install it
2) Restart Windows (you may get some .sys error messages after rebooting)
3) Set the SciTech GLDirect Configuration program to Win 98 compatibility
4) Run it, save the settings
5) Open up Terranim8or and see if it worked.
You should read up on this page:
http://biederman.net/leslie/terranim8or/instructions.htm also. And then email Leslie if nothing works.