Windows 7: Laptop Wont Go To Full Resolution

I decided to upgrade my parents laptop to Windows 7. The installation went fine but for some reason the laptop itself won't go to full resolution, The laptop in question is a Sony Viao PCG K315S. I just wonder if anyone has had the same problem and been able to fix it.

What was the recommended resolution before upgrade? What is the currnent recommended resolution?

Its native is 1280x800 and it's currently stuck at1024x768.

Driver. Update the video driver.

In general with Microsoft Windows when you are stuck at a low resolution you most likely do not have the correct driver installed for your graphics card. Windows uses sort of a "default driver" which works with almost any hardware, but with very limited functionality. If you do not know what graphics driver you need, you may want to download and use GPU-Z.

I tried to download and install the newest Win732bit Mobility driver from ATI website but it won't install. It says the hardware (ATI 9200) isn't supported. There are Legacy drivers on the site, tried the WDM driver, that went in no problem but didnt give me any more resolutions to choose from once installed. I tried to install the full software suite too, that didn't want to install either due to it not finding compatible hardware.

I found this thread 9200 Windows 7 driver help. - Guru3D.com Forums and downloaded the custom driver but not sure how to install it. I tried updating via Device Manager but it wont accept it, is there a way to install it manually?

Anybody?