I have a Dell XPS 15 (L502X) running Windows 7 with an Nvidia GeForce 525M (If I recall correctly. Can't actually check now that my laptop won't detect the card.)
I'd been having problems installing drivers for my video card, and while fooling around with settings in the device manager, I managed to completely deactivate the card itself. The system won't detect the card at all, I can't install any Nvidia drivers because the installer doesn't detect that I have Nvidia hardware on my laptop, and the Nvidia control panel program won't start. Any help with reactivating the card would be very much appreciated!