Flickering at low frame rates

Hi

I’m slowing down my application to save some CPU time by using multimedia timer. I trigger my Display function every 40ms but then (besides everything is slowing down) the flickering occurs. When I trigger it every 10ms the flickering dissapear, but the CPU is highly overload (90%)
How can I remove the flickering in the low framerates? I’ve read about the WGL_EXT_swap_control extension, but I don’t know how to use it. Can someone send me an example?

Regards,

To draw once every 4 monitor refreshes :

wglSwapIntervalEXT (4);

you call it just once right after OpenGL initialization.