There is often a key to tap during boot that allows you to select a
one-time change in the boot device - [F12] is a common one but have
seen [F11], [F10], [F9] and [F8] used for this !! Sometimes the option
needs turning on in BIOS too.

Next thing to look at is the Hard Drives listed and some BIOS's need to
to change the USB device to the first in the list but it will only
show this when the thing is plugged in.

A system that new *will* be able to boot from a USB device, just need
to work out the way yours does it

On my Linux and XP windows machines when I plug in a
USB drive, it sometimes says "Removable Device" depending
on make of drive. My guess is try the Removable Drive option.

Removable devices would be 1, cdrom 2, and 3 is hard drive. Removable is just
generic term for any USB drive, SD card, or Mini Flash. No harm is going to come
of changing the boot sequence. Unless it has Create Giant Vortex option and if
you have that option. For the love of humanity please do not select that. Unless
you been trained by Doctor Who or some none Red Shirt Space Federation officer.
Never a Red Shirt, because the life span for one is short lived. Basically a Red
Shirt is to the equivalent of an American Red Neck. When you hear "Hey ya'll
watch me do this"! You know some one is going to die.

> Removable devices would be 1, cdrom 2, and 3 is hard drive. Removable is just
generic term for any USB drive, SD card, or Mini Flash. No harm is going to come
of changing the boot sequence.

Many thanks for your replies. I wasn't sure... i'm more familiar with
older machines when it comes to tinkering and on those i recall having
a drop down menu and one selected from a list like A, C, E or E, A, C
(or similar) where A was the floppy, C hard drive and E was CDROM.

Something i should have looked into before but i'm afraid i have a
busy time looking after my mother with Alzheimer's so i don't like to
be too venturous as i depend on the PC for loads of things... and
couldn't stand the thought of messing it up somehow.

Gobby nice to hear from you... think you were the person to reply to
my first post on here when i started using ubuntu in 2007. I've now
been a xubuntu user for about 3 years and have to say i've had few
problems. I did look at some other distros over the last couple of
weeks but have to say none of them for xfce compare with xubuntu (i
love the minimal environment which i add my preferred apps to).

Just out of interest; is usb stick or SDHC better. Having had a usb
fail i'm putting faith in SDHC... just wondering what you're
experiences are (depends if one's got a SDHC drive of course).