|Too late now but all he needed to do was download or enable the graphics driver for your onboard video.|
If your present dilema is a BIOS setting then he must have gone there to disable it. Might be worth you asking him because that would not be the most likely thing he did. If not let us know exactly how he disabled it.
There is a greater possibility he did it in Device Manager. In which case tap F8 while booting and select Safe Mode. Go to Device Manager and enable the Display Adapter again.
Ms Hulot's boat