When I installed Windows 7 RTM on my Sony VAIO laptop I discovered the same problem as when beta testing WindowsVista some years ago. The problem is that drivers for the video card for Nvidia mobile graphics chipsets is missing which means running with the feature lacking and slow Standard VGA driver.
In all releases of Windows 7 up to RTM there has been a driver available via Windows Update for the Nvidia mobile card but this driver seems to be pulled from Windows Update (and Microsoft Update Catalog). If you did not already know it Nvidia offers drivers for many of its mobile graphics chipsets on www.nvidia.com, but unfortunately these drivers do specifically not work on SonyVAIO machines.
The solution to install the Nvidia driver anyway is to download and unpack the driver from www.nvidia.com and then modify one of the INF files to make it support your video card. May I mention that this solution is not support in any way, but the important thing is that it works.
In my case I looked up the hardware ID for my Nvidia GeForce 8400M GT in device manager and found out that is has the hardware ID “PCI\VEN_10DE&DEV_0426&SUBSYS_9005104D”. Then I went to C:\NVIDIA\DisplayDriver\186.03\International\Display (the path might differ when using a newer driver) which is where the files are unpacked when you run the downloaded driver. Then I opened nvam.inf and added the below two lines where there are similar rows in the INF file.
Note that the “0426” part in the beginning of the first and second line is derived from “DEV_0426” part in the hardwareID which is unique depending on what graphics card it is. In my example the lines I am adding looks like:
NVIDIA_DEV.0426.01 = "NVIDIA GeForce 8400M GT (Sony Vaio FZ38M)"
%NVIDIA_DEV.0426.01% = Section012, PCI\VEN_10DE&DEV_0426&SUBSYS_9005104D
If you look in the INF file it will be quite obvious how to proceed. Then run setup.exe or install the driver manually. It should work like a charm ;)