Why does my Asus A8N-Sli board not detect pci devices?

Alright... i guess i will start by saying that my PCI slots DID work. The only thing that I have plugged into my PCI slots is my Creative X-Fi soundcard. Things were always fine with that other than some driver conflicts with my ATI card. However, there was a time when windows was having difficulties with games so I set the BIOS settings back to default (forgetting that the AC '97 onboard audio would enable). Windows would not get far before it locked up. It would not even get to the login screen. Ever since then, Windows has not been able to detect my X-fi soundcard. I have changed ports, cleared the CMOS, and just about everything else I could think of. Please let me know if you could think of any reason why this could be! Also, I wanted to add that nothing shows up in device manager for sound. I have the onboard sound disabled for sure this time.

OH AND ON A WEIRD POSSIBLY RELATED NOTE! Whenever i tilt my case to the side or plug something into the back of it in a forceful way.... my pc will shut off! Just a hard shutdown! I have no idea what the cause of this would be. I have rewired everything and checked for any loose connections whatsoever. My powersupply is a 550W Rosewill.

 

sorry.... just noticed that i posted this twice! I just wanted to say to ignore the comment about the powersupply. It turns out that I forgot to plug in a small piece on the ATX power connector to the powersupply. I guess my only problem is the sound now.