You may find what you are looking for at http://www.codeconscious.com/outlook-express/backup-outlook-express.html

If all seems to fail you should be able to open the message folder that will not import or export, select all of it's contents (emails/messages) right click, copy then paste to a newly created folder on the other machines OE. Even if you must do this via a CD it should work.

Hope this is of some help.

Charlie