I installed Ubuntu and everything went ok. I did it by looking at this guide
http://www.linuxbsdos.com/2011/05/23/install-ubuntu-11-04-on-external-hard-disk/
Then when it boots from USB I get this error at the begining while booting
disk drive for boot is not ready yet or not present
According to this guide method 1 I went to grub/grub.cfg
(since in GRUB 2 its no more menu.lst) and changed all /dev/sdc
to /dev/sda
as the guy says in his guide, but after these changes it still gives me the same error message. Can anyone help with this issue?