FATAL: No bootable medium found! System halted.

[Amazing Blair]

I get the following error when I attempt to start up Windows 8 under Ubuntu Linux for the first time.
"FATAL: No bootable medium found! System halted." There is a bootable System Disk version of Windows 8 in the CD drive but it doesn't seem to read it. The boot order is Floppy, CD-ROM, Hard disk.

The really weird thing is that in a small minority of the tries, VirtualBox DID read the DVD! It got as far as displaying a light blue Windows logo, and then said the PC needs to reboot (octal error code 5D). I was going to ask how to send a "cold boot" signal into VirtualBox, but I'm back at the "no bootable medium" problem so I'll start with that.

Host OS is Ubuntu 14.04, 12 gigs of RAM, 2 terabytes of disk space.
Guest OS is Win 8, 1 gig of RAM, 150 gigs of disk space.
VirtualBox is version 4.3.10_Ubuntu r93012 .

Any help to a newby is appreciated.
-Blair

[Amazing Blair]

PS: Ubuntu is 64 bit, Windows is 32 bit.

[socratis]

Maybe your CD is bad and sometimes it can be read and sometimes it can't? See if you can make an image (iso) from it with a program that has error correction for reading CDs.