“No bootable device - insert boot disk” after restart on Ubuntu 10.04 b1 update

Question

I was making an update on my Ubuntu 10.04 beta1 64-bit PC when, after reboot I get

PXE-E61: Mediaa test failure, check cable PXE-M0F: Exiting Intel Boot Agent.

No bootable device - insert boot disk and press any key

How did my boot record disappear ?

BIOS > Boot

Boot Menu Type : Normal
Boot Device Priority : <CD/DVD-ROM Drive>
                       <Hard Disk Drive>
                       <Floppy Drive>
                       <Ethernet>
Hard Driver Order    : No Hard Disk Drive
CD/DVD ROM Drive Order : <PT-TSSTcorp CDDV>
Removable Drive Order : No Removable Drive
Boot to Optical Devices : <Enable>
Boot to Removable Devices : <Enable>
Boot to Network : <Enable>
USB Boot : <Enable>

Answer 1

Tried all sorts of things - finally opened the chassis - for some odd reason the cable connecting to the hard-disk got burnt. The computer was on the whole night though, but that shouldnt be a reason. Shouldnt be a voltage issue as Im connected to a 1kVA Delta UPS which handles the voltage fluctuations (if any).

Answer 2

Sounds like a grub (bootloader) problem. I'd suggest booting from a live CD, mount the file systems from the disk, chrooting into them and using grub to re-install the bootloader.

I am of course assuming that you know how to do the above, based upon the fact that you're knowingly running a beta release operating system.