Problem with SiS UniVGA3 Graphic driver

Hi guys i'm new, my problem is with the driver of my graphic card is a
SiS UniVGA3 or SiS mirage 3 i don't sure, but i try download the drivers and it says: "instfunc.exe not found" i'm using the driver Genius to download and this is my PC:

Windows 8 (With 7 and vista it's the same problem)
Foxconn:
Model: 662M03
Bios: Phoenix-award Bios V6.00PG
processor: Intel Pentium Dual Core 1800Mhz
Ram: 1024
DirectX: 11

Pd: i don't have opengl and i need it, please help!

Pd2: If i need change the OS i will.
Thanks and sorry for my bad english, I'm from colombia