ok one for all the IT Nerds out there. I turned on my computer tonight, hadnt had any known problems with it as yet, and after the first boot up screen it goes to the motherboard logo screen usually for about a second then would go to windows, tonight thou it stays on the motherboard screen for aaages then after a minute or so goes to a black screen sayin this

"reboot and select proper boot device or insert boot media in selected boot device and press a key"

what the hell does this mean and what the hell do i do lol? never had nay probs before this tonight.