I have recently come across this problem. The computer has been running fine for months with no changes at all. I got up this morning, switched on my monitor, and I had a message on my screen,
Reboot and select proper boot device or insert boot media in selected boot device and press any key.
I keep my computer on 24/7, doing a reboot every week or so and never had this problem before.
I did a ctrl alt del and it started to reboot. Took a while to get going but went back to the same message. I turned off the computer completly and it booted fine. I went to work and came home to the same message.
I was thinking a format may be in order or does any body else have any other solutions to the problem