Problem with DirectX on my computer

I have a little problem with DirectX on my computer xp evolve and function DirectDraw worked well but since I installed Vista no longer works when I type dxdiag in run and they tell me display DirectDraw not available videos walk very slowly I do not know whats the problem

Can someone help me ?

Thanks

Make sure that your video card and driver are compatible with DirectDraw.

I have a problem since I reinstalled XP on my computer (move to a pro version). Suddenly a window tells me "a critical error has occurred while initializing DirectDraw"

After a test video, windows says "video mode not found"
Do you have a suggestion for my problem?

if you lower the security of vista maybe it would solve the problem. I'm not an expert in vista but I had similar problems and solved it myself so ...