GPU selection problem

Hi, I’m trying to do a GPU selection with WGL_NV_gpu_affinity extention over NVIDIA Tesla M60 graphic cards, I checked previusly that these graphic cards support WGL_NV_gpu_affinity extention with GPU_Caps_Viewer tool, but the two function pointers that I’m using for the functions wglEnumGpusNV and wglCreateAffinityDCNV are NULL, I’m getting these function pointers through the wglGetProcAddress function and the memory address of this function isn’t NULL. I will need a help with tis topic. Thanks