Problem with Garry's Mod, Also a display driver issue

[Vexua]

Since I have upgraded my Ati 6770 to a Nvida 570 Garry's Mod has been shutting down as soon as it hits the loading screen, and I have no idea whats causing this. Also instead of making a new thread I need help explaining why my video driver stops responding whenever I start the first game of the day, and it doesn't matter what I launch it does it for any 3-D game

[djjkxbox360]

You did uninstall the ati video driver before you put the new graphics card in right? Try reinstalling the driver

[Vexua]

Yes, I uninstalled all AMD products, and I will try to reinstall the driver

[editline]18th August 2012[/editline]

I just finished uninstalling my drivers and the display driver is fixed, but Garry's Mod continues to crash for no apparent issue