Sony VAIO Vgn-sz430n Drivers

I have a sony vaio vgn-sz430n running Windows Vista Business. I upgraded to Windows 7 and it went off without a hitch until the first log in. The desktop will not fill the screen and it only gives me two options for resolutions: ~1024x768 and 800x600. I went to device manager and found that my display driver is now standard vga driver.

The laptop has an nvidia geforce go 7400 graphics card and, from what I've read, it also shares memory with onboard integrated graphics...I think. I read other threads suggesting methods to fix this problem but none of them have worked. I tried downloading the windows 7/vista driver for that nvidia graphics card from nvidia but the setup program says no compatible hardware found.

I tried pointing Windows 7's driver installation (from device manager) to the driver's location in the setup folder but it tells me the most current driver is already installed and no update is needed. I even tried modding the driver (as suggested on another thread) but that didn't work.