If you know how to edit the registry correctly:
Start | Run and then type regedit
Locate the following key in the registry:
In the left pane, click Outlook Express. Two values should be displayed in the right pane: one is Default, which has a value of Outlook Express, and the other is DLLPath, which contains the path to Msoe.dll on your computer.
If the DLLPath value is not present, click Edit, point to New, and then click String Value. New Value #1 is displayed, with the text selected. Type DllPath, press the ENTER key.
Double-click the new DLLPath value to open it. In the Value Data box, type the path to the Msoe.dll file on your computer, for example:
C:\Program Files\Outlook Express\MSOE.DLL
Click OK, and then quit Registry Editor.