Switching back to d3d

[Dry-Synapse]

Hey guys, my problem started when i was trying different settings for cs on my new computer with vista, (it wasnt running very smoothly in opengl but still working, switched to D3D...looked better..) when i foolishly switched it again to software mode and now every time i try to open up any game that runs on my graphics card not just cs i get a black screen and cant even ctrl+alt+del. out of it. have to hit the on button to restart. I need to know a way to set the graphics option on my computer back to D3d or opengl without going in through cs options on vista. appreciate any help.