Have you tried the drivers directly from nVidia? NVIDIA DRIVERS 260.99 WHQL
(These are supposed to support the 8800M GTS. The M stands for Mobile, as in notebook.)
I suggest these because Sony has no Windows 7 drivers for your notebook at their web site. If the nVidia drivers above can't recognize your graphics device, I suggest trying the Vista drivers: Sony eSupport - VGN-FZ283BN - Software Updates & Drivers
If those install successfully, try installing the nVidia drivers (above) over them. I had to do something like that with my Compaq notebook, nVidia 8200M graphics.