This morning my display wouldn't turn on when I booted up my computer. I swapped the video card and now get the message "Reboot and select proper boot device or insert boot media in selected boot device and press a key." I checked all connectors, and they seem to be good. When I go into the repair option on my Xp disc, it says it did not find any hard disk drives installed on my computer. No hardrive show up in Boot device priority in bios either. What could be the problem? Is it the power supply?