Yes.. you need to go into 'Tools', 'Options', 'Maintenence'
Then hit 'Store Folder'.. this gives you folder name and path.. i.e 'C:\Windows\folder\etc'.. select the path and 'copy' (Control + C)
Open Windows Explorer.. go to the address bar, paste in your path.. then the folder opens..
You'll see loads of DBX files or something similar. Copy all of these and if you ever re-install just paste them into the new 'Store Folder'.. then when you restart Outlook Express the messages and folders are magically restored!
You may be able to download software which would 'decode' or show the contents of the DBX files.
I have about 800MB or 1GB of emails which I copy in the way I've said above.
Cheers