Help outfitting my computer

[Blackflare]

I'm not sure where this should be posted, so I thought I might as well put it here. My problem is m video card, I need a new one to run ffxi. The bigger problem is that I'm unable to install the card I bought. I brought in my computer to the store and they helped me pick one out. I got it put in and installed all the drivers. Unfortunetly, I have a sony vaio, pvc-rx741 if that helps. And it's onboard vga is impossible to disable. The kind folks at pny had me try it the normal way, and then through bios, and was unable to get it disabled. I really need a fix to this, if anyone has gotten a video card to work on this type of computer please tell me how.