Ensure that your .DBX files are not Read Only
Your .DBX files are the store files for your Outlook Express folders. If your files are marked as Read Only, they cannot be accessed. An example of a cause of this would be if you recently restored the files from a backup on a CD-ROM. To remove the Read Only attribute, perform the following steps:
Click Start, click Find (or Search) and then click Files and Folders.
In the Name field, type *.dbx, and then set the search to include local hard drives.
Click Find Now or Search Now, and when the results are displayed, click the In Folder column heading to group items by location. Note the locations of the files found and then use Windows Explorer to navigate to the directory that contains your current store.
Right click the first file in the folder, click Properties, on the General tab, click to uncheck the Read Only check box, and then click OK.
Repeat step 4 for each file in the folder and test Outlook Express.
Regenerating the Identities Registry Key
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To regenerate the Identities registry key:
Click the Start button, click Run, and then type regedit. Click OK.
Browse through the registry to the following registry key:
HKEY_CURRENT_USER/Identities
On the Registry menu, click Export Registry File.
In the Save In box, click Desktop.
In the File Name box, type Identities, and then click Save.
In Registry Editor, right-click the Identities key, and then click Delete.
Quit Registry Editor, and then start Outlook Express to test functionality.
You can now restore your mail, addresses, and account settings.