I recently installed Ubuntu 12.04.1 TLS on one of my servers running Windows Server 2008 R2, following a reboot BIOS was stuck with an error message indicated that no valid media was inserted that allowed it to boot.
I verified and re-verified boot order, no problem, hard drive was indeed detected and first in boot order. I put back the DVD reader and started the server with Ubuntu Live CD.
I then noticed that the recently installed Ubuntu was indeed there and well installed by mounting the partition.
Issue was with the Grub, to repair it using Boot Repair from Ubuntu Live CD:
- Connect to the internet.
- Open a terminal, add the repository and install boot-repair.
- Then start Boot Repair and choose ”Recommended repair”.
- Remove the Live CD and reboot the computer, it will start correctly on the hard drive.