Sharing Outlook Express’s mail and news group accounts between users in Windows XP
 

If you are not bothered by rules, signatures and all the other settings the same, this tip works.
From the account that is already set up. Click Start navigate to Run and type-in REGEDIT
Locate the following four branches of the Registry:

HKEY_CURRENT_USER\Identities
HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager
HKEY_CURRENT_USER\Software\Microsoft\Outlook Express
HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4\Wab File Name

Right click on each branch and choose Export and save the REG files to your hard disk.
For every account you want to have the same mail settings, log into that account.
Click Start navigate to Run and type-in REGEDIT. Locate the HKEY_CURRENT_USER\Identities branch, right click it and choose Delete.
Open Windows Explorer and locate the four REG files you saved. Double click each one and respond yes to the import prompt.

Now you can open the Outlook Express in any of the User accounts and settings, accounts, will be the same.
Tested on a FAT32 drive but not sure it will work on an NTFS drive.

Note: You will also need to re-enter the passwords for mail and news group accounts.
If you use Signatures, you have to put them in a text file and change the settings of the Outlook Express to use them.
Signatures are often corrupted during the import, due to the Unicode storage of the signatures in the Registry.