When you install Windows 7 as a fresh install you will still get a reasonable screen picture as the computer loads a standard vga driver. But then you will want to update your graphics driver to get better graphics for games or such!
Here is how I did it-
How I installed the latest Nvidia M 186.81 notebook driver to my Sony Vaio VGN-AR51E laptop.
Sony is supposed to supply the drivers but they don't for some reason.
The latest laptop drivers from Nvidia work if you alter two lines of information in the appropriate inf file before executing.
I downloaded the latest driver from Nvidia (186.81) and ran it so it unpacked into a folder in my C drive. [Message box says it won't install].
From Control panel I got my driver hardware ID
Control panel / Device manager / Display adapters / Properties / Details / Device description/
(You just need the second line here)
Then I opened up the Nvidia driver package and altered NVDM.inf file, in the Display folder, by adding two lines to include my hardware ID
(as you scroll down the inf file and study, you will see where these go, in two different list sections)
%NVIDIA_DEV.0426.01% = Section005, PCI\VEN_10DE&DEV_0426&SUBSYS_9016104D
NVIDIA_DEV.0426.01 = "NVIDIA GeForce 8400M GT (Sony Vaio AR51E)"
I included my ID also in ListDevices.txt in the NVDM.inf section
and in modes.txt (but may be superfluous - I am no expert!)
Also I put the two lines in the NVAM.inf (but may be superfluous)
Don't forget to save all.
I deleted the old Nvidia driver rebooted and ran setup on the new Nvidia driver! It worked!! Hope this helps you. PYL
Or you could also try NVIDIA MobilityModder - DriverHeaven.net