I installed 13.10 just yesterday and it didn't detect my Nvidia 420m GPU. i am using a dell xps laptop with optimus. I checked in software update app-->Additional Driviers but the drivers option didn't show up. When I installed 12.04 LTS a month ago, it automatically detected nvidia card and updated to v319(recommended) drivers.Now it just doesn't detect at all. I am new to ubuntu, help!