Bug#1101326: grub-common: Cannot switch back from UEFI to Legacy Mode

[Pascal Hambourg]

The BIOS is probably trying to boot from the wrong disk.

You can install GRUB on the hard disk, let the machine boot 
automatically and, if it shows the GRUB menu, enter grub shell and check 
the output of 'ls'. If it shows hd0 (the boot disk) with one partition 
and hd1 with 5 partitions, then it means that it booted from the hard disk.