VGN-Z790Y - Docking Station w/Second Monitor

Hello,

I am running out of ideas and turning to you for additional assistance. I have a user with a VGN-Z790Y on a Z Series Docking Station. I am not extremely familiar with the Sony hardware which may be a bit of a hindrance at the moment and it also doesn't help that the user is on the opposite side of the country so I can't really get familiar with it. He has had his Vaio docked with a second external monitor, thus achieving dual monitors, for quite some time now. Something happened between last night and this morning that causes windows to throw this error message anytime you do anything with the display:

The currently selected graphics display driver cannot be used. It was written for a previous version of Windows, and is no longer compatible with this version of windows. The system has been started using the default VGA driver. Please contact your hardware manufacturer to get an updated driver, or select one of the Microsoft provided drivers.

I understand this model has a hybrid video system, which I didn't know existed until today.
I have tried:
Reinstalling drivers from sony website, installed but did not change a thing.
Used sony driver cleaning utility under the Windows 7 downloads section, didn't seem to help.
Installing nVidia drivers from nvidia website, failed.
Installing Intel drivers from Intel website, failed.
Disable/Enable in device manager, renders higher resolution when disabled but not native or external monitor.
Rebooted numerous times, no change.
System restore to a few weeks ago, no change.

I feel the issue isn't related to Vista at this time, but could be wrong about that. It seems that there is an issue interfacing with the docking station because when he pulls his laptop off the dock he can run the laptop display at native resolution and connect his external monitor and run it just fine. Is there an additional video card in the docking station? Perhaps it is damaged or is having an issue with the hybrid system? I am not any more confident as to the issue right now as I was when I first encountered it this morning.
The OS is the pre-installed version of Vista 64. Thanks for your time and I appreciate any input anyone has.

 

I was wondering if anyone knew the best way to verify what video card you are running on? When I have my user flip between Stamina and Speed I want to verify that the video switch is actually occurring. Is there any con/pro to reinstalling the video driver in specifically Stamina or Speed?