Update NVIDIA Graphic card driver for SONY laptop

Steps:
1. Get the latest driver from NVIDIA and unpack it.
2. Look up the hardware id of the Graphic card in Device Manager -> Display adapters -> NVIDIA GeForce 8400M GS -> Properties -> Details tab. Select "Hardware Ids" from the Property dropdown checkbox and then it will be listed. There should be something like PCI\VEN_10DE&DEV_0427&SUBSYS_9008104D. Here 0427 after DEV_ is the hardware id.
3. Go the driver folder unpacked earlier and locate nvam.inf (in driver folder) and open it with any text editor. Find the entries start with %NVIDIA_DEV.0427, and replace the value after SUBSYS_
Ex.
From %NVIDIA_DEV.0427.01% = Section001, PCI\VEN_10DE&DEV_0427&SUBSYS_17C21043
To %NVIDIA_DEV.0427.01% = Section001, PCI\VEN_10DE&DEV_0427&SUBSYS_9008104D
5. Save the nvam.inf
6. Run the setup.exe to install the latest driver