OpenGL lockups!

I have a TNT2 m64 working for general Windows display purposes. When I try to run OpenGL demos though, the system locks after a second or two.
The previous graphics card I had used a MCD, and the new one uses the ICD.
In addition to finding out why this is happening, I would like to know the process that occurs that initializes the ICD. I mean, I have the nvOpengl.dll, the windows OpenGL32.dll, etc. What calls what, should something be renamed/deleted, etc?