i have a Qosmio X500 10W.
I should update the display drivers to be able to play Bad Company 2, but the last nvidia drivers avaible on the Toshiba website didn't fix my problem, and i fail installing drivers downloaded by Nvidia website because it says that they are not compatible with my device.....
Qosmio serie is made for gamers, so i hope that this problem will be fixed ASAP.
Qosmio x500 is newest notebook model and I presume Toshiba used latest driver designed for mobile computing. Maybe new version will be released soon.
Drivers from NVIDIA page are not designed for mobile computers and that is the reason why you didn't install this version.
Be also careful with NVIDIA drivers. Yesterday I found article about bad driver Version 196.75. Result is graphic card overheating.