Help me plz

[Boots_1]

Hello,
i built a computer a few months back, everything worked great! now for some reason this message pops up when i ture the computer on. reboot and selecr proper boot device or insert boot media in selected boot device and press enter.
can anyone help me plz.
what i run.
asus p8p67 deluxe with
windows 7 64 bit

 

[Onus]

Reset BIOS to defaults, then check boot order and make sure the desired hard drive is listed. If that fails, check your hard drive's physical connections for a loose cable. If that fails, plug it into a different SATA port on your mobo to check for a failed port. If that fails, your hard drive may have croaked.

 

[misry]

Is there a disk in your CD drive?