I have problems with speed under OpenGL

OpenGL OpenGL: Basic Coding
1

I have GeForce3 Ti 200 and last drivers from nVidia are installed. I overlooked video card using RivaTunner. After that all OpenGL applications began to work very slowly. I put default value for core clock and memory clock, but nothing changed…
Can somebody help me with something?
Than you.

2

Does everything you run, run slowly? Or just one program?

3

Any OpenGL application run slowly, but DirectX applications run normal… I installed DirectX 9, but I think that it can’t influence OpenGL.