Hmmm. PCI-E 1.1a only supports PCI-E 2.0. There may still be a chance that you can run a much better graphics card, But just incase if i were you i would get a 8800GTX, which is the only significantly better PCI-E 1.0 graphics card.
Good luck to you.
PS: try Updating your drivers by going...
Hi all
I know im new, but ill keep things brief.
I just got another asus EN9600gt to go with my leadtek PX9600GT on vista Home Premium 64x
For a while it worked (sli could be enabled, but NO difference in FPS/ 3dmarks). then i got new drivers and it screwed up and my second (the asus 1)...