Hi Russel,
i have found this part of an article made by microsoft
CAUSE
When you installed Microsoft Internet Explorer 4.0 and Microsoft Outlook
Express, you selected the option to make Outlook Express the default Simple
MAPI client.
NOTE: In some cases, a corrupt Mapi32.dll file has caused this problem.
RESOLUTION
Do not use Outlook Express as your default Simple MAPI client.
-or-
Rename and reinstall your Mapi32.dll file.
To Reset Your Default Simple MAPI Client
Start Outlook Express.
On the Tools menu, click Options.
Click the General tab, then click to clear "Make Outlook Express my Default
Simple MAPI client."
Restart Windows.
To Rename and Replace Your Mapi32.dll File
Right click on the Mapi32.dll file in your WindowsSystem folder.
Click Rename on the Shortcut menu.
Type Mapi32.old as the new name for the file.
Copy the Mapi32.dll from the OFFICEWMSWIN95 or OFFICEWMSWINNT folder of your
Office 97 setup compact disc, into your WindowsSystem folder.
In the Windows Explorer, click the file you copied to your hard drive, and
on the File menu, click Properties.
Click to clear the Read-Only check box, click to select the Archive check
box, and click OK.
Close the Explorer.
