how to give switch card option?

my primary card does not support opengl (at least i think). it is a SIS6326 and my secondary card is a voodoo2. All my openGl apps run very slowly with this card and i would like to know how to change the 3d card used when running oepnGL apps. I cant disable the sis card so i need to know how to do it in code. Any help would be great… thanks

Franky G

Although I havent tried it I think you need to use EnumDisplayDevices to get info on your cards. Then use CreateDC with the info you got from EnumDisplayDevices. After that you need to use EnumDisplaySettings to get the display modes and then use ChangeDisplaySettings with that info. The DC you got from CreateDC will be the one you use for the rendering context. Make sure you save the display mode before you change it so you can change it back.