I somehow made it impossible to use a PCI Express card on my ASUS A8N-Sli motherboard. This is what I did. I put a Diamond Supramax PCI modem card in the bottom PCI slot on my motherboard. This modem had been working in another computer. But now it caused the system to crash and when I tried to reboot, my ATI X1800 XL video card would not post. There was a long beep and the audible message: System failed VGA test. This keeps occurring even after I took out the modem card!!
Since I couldn't get into the BIOS I put an old PCI video card in one of the PCI slots and it booted up fine. Then I tried to go into BIOS and find out what might be wrong. I tried a couple of things, like making my PCI Express the primary boot and choosing Single video card but nothing works. I went into system to see if there was an Interrupt conflict but couldn't see anything wrong there either. Does anyone have a suggestion?