I have a Gateway laptop running XP Media Edition. I use a 250GB ext HD for my
iTunes and other programs I do not want to bog down my laptop. I sometimes
need to remove the ext. HD (via safe removal). The problem arises when I
reconnect the HD and the drive letter has changed. This messes up my short
cuts and causes problems with software updates, specifically iTunes. My
question therefore is, can I permanently assign a drive letter for my ext.
HD? And if so, how?
Thanks!

By design, Windows XP assigns the next available drive letter to storage
devices so, as you have found, you cannot permanently designate a drive
letter.

There are work-arounds for this common situation (which was not common
when XP was being designed.) I'll present two work-arounds here.

The method I use is to dispense with drive letters altogether and use
NTFS mount points instead. While you won't get a drive letter, you will
have a fixed path to your device which will not change and which can be
substituted for a drive letter in many if not most applications. You can
find a fuller explanation here:

http://aumha.net/viewtopic.php?f=62&t=28888&start=0

Another very effective method, one that will allow you to choose a drive
letter, is Uwe Sieber's USBDLM, a Windows service that gives control
over Window's drive letter assignment for USB drives. You can find it here:

http://www.uwe-sieber.de/usbdlm_e.html
---
Leonard Grey
Errare humanum est