|Unfortunately With your Presario S6500NX, there is no manual overide either in the BIOS or on the motherboard, and this is not uncommon OEM's.|
Installing an AGP card automatically disables the onboard video. You just make sure you've removed the prior drivers and check device manager, then install the 9600XT AGP card.
BTW....when posting on a forum avoid block messaging, it makes your thread heck a lot easier to follow.
Leadtek sucks BIG TIME