if your onboard grphics does not show up under device manager then it is disabled. But to double check reboot, press either F1 or esc to get into yuor Bios, and go to advanced management, and see if it say's main source for video is AGP..
The software is hydravision, the drivers are the catalyst.
as for overclocking here is some stuff you can read through...
http://www.pchelpforum.com/component...0/topic,1744.0