what is the procedure for installing a video card in this machine? Have already upgraded psu to 480w. Has nvidia 7050 (620i) integrated chip.trying to put nvidia 9300GS card in and after disabling driver for onboard, restart,enter BIO'S disabled vga memory share,auto initiate pci-e and plug in to card output and just get black screen.Plug back into onboard output and everything is back to normal. But it would be great to be able to use the card since onboard is minimal at best. Any help much appreciated.