Color-Index Mode @ WinNT

Trying to get 'aaindex.c' (Redbook Example 6-4)to run on a WinNT station, I receive the message: "GLUT: Fatal Error in (path...).exe: visual with necessary capabilities not found".
Using: "glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);" instead of: "... GLUT_INDEX);",
it compiles and runs normally. What am I doing wrong and what is a "visual"?

[Antoche]

Maybe you should try with RGBA instead of RGB (i got som problems with that on several machines).
If it doesn't work, then your graphic capabilities are just too poor for your programs. What's you video card ? maybe you must change it.

[David]

I have had this problem as well with the color index example, im using a Riva TNT card with 16MB Ram. Would it be a hardware problem? Oh and im running it in 98 not NT, and im still getting the same error message.

Any Ideas?