HP notebook USB drive boot install
 

hi friends
I succeeded in installing Ubuntu AMD 64 last release on USB hard-disk but when I boot I get error 17: cannot mount this drive...or something similar.
I said to Ubuntu to write boot information on that drive and not on the main (windows).
can you help me?
thanks in advance

So, when you installed Ubuntu on your USB-drive you told him to write the MBR as well on the USB-drive, is this correct? And now, after that you set up the BIOS of your PC to boot from the USB-drive, it starts reading the MBR of the USB-drive an then you get an error saying what exactly? That it cannot mount the root partition?

yes
 

yes
error 17 "impossible to mount partition" with slave usb hd
and
error 15 (no text) with master.

Perhaps the configuration of grub is not correct? Don't know with Ubuntu, but with Gentoo there is a file in /boot/grub/ called "grub.conf" (or perhaps "menu.1st") which contains the configuration of the partitions and where to find the root partition. E.g.:
In your case perhaps the "root (hd0,0)" and/or the "root=/dev/sda3" might be wrong? Well, not exactly "sda3", but whatever is mentioned there in your config?
:confused:

In order to boot from a USB drive, the BIOS of your computer must support this. That drive must be mounted and accessible to the system BEFORE grub (or any other bootloader) is invoked; this can ONLY happen if the BIOS does it.

Sounds to me like either your BIOS does not support this, OR it is not enabled in BIOS.

Your remaining alternative would be to, for instance, set up a boot floppy or a boot CD, immediately enable USB and identify the drive, then and only then do a pivot root to get to the drive and boot from it.