We don't know what two OSs that you are using so the exact registry key may be in a different location. Here is a registry hack that works for mapped network drives. It might just work for a local folder as well.
**Do this only if your comfortable with editing the registry. Back-up before modifying, make ERD, bla, bla...
According to Microsoft, the Outlook Express message folder must be located on a local hard disk, not on removable media or a network share. But it's possible to overcome this limitation - that's the good news. The bad news is that moving the location of the mail store to a mapped or removable drive isn't supported by Microsoft, so you use the following information at your own risk.
This hack applies to Windows 95 or Windows 98. Load the Registry Editor, RegEdit (having first taken a security backup of the Registry) and drill down to the registry key: HKEY_CURRENT _USER\Software\Microsoft \Outlook Express. Right click on the Store Root value to edit it, changing it to the desired network share or path. Note that if user profiles are in force, the Store Root value is located in the registry key: HKEY_USERS\username\Software \Microsoft\Outlook Express. 'Username' is the name you use to log on to Windows 95/98.
Things are slightly different in Outlook Express 5.x as it lacks separate Mail and News folders because everything is now held in .DBX message stores - Inbox.dbx, Sent Items.dbx, and so on.
The registry location for Outlook Express 5 is: HKEY_CURRENT _USER\Identities\{idnum}\Software \Microsoft\Outlook Express.
A good resource for additional information is
here.
