Outlook Express

[Vivian]

I have had problems switching b/w users. Sometimes when I
switch users my computer reverts to the desktop and I can
then no longer access the Outlook Express. I have had to
restart the computer in order to reaccess Outlook
Express. This only occurs sometimes..it appears to happen
if I send an email prior to trying to switch users.
Strange! We have recently installed Windows XP
Professional and I am using Outlook Express instead of
Outlook b/c I feel more comfortable with Express. Any
ideas about what is going on?