HP Pavilion Display adapter drivers

I am working on an HP Pavilion 6605. It has integrated AGP 3D display graphics with 8mb of shared video memory. This is written on the computer. The HD has been formatted and the owner has lost all the software! Windows detects the display adapter and installs it as a standard vga. It will only display 16 colors. HP support do not offer any drivers that I can find and they will not even tell me what the adapter might be so I can look for the drivers myself. I have opened up the computer and looked but I can’t find anything. I have never struck integrated display before so I don’t know what I’m looking for.

Is there a generic driver? Or can someone tell me how to identify the adapter? What about some sort of diagnostic utility?