To resolve this problem, reinstall Microsoft Outlook
Express or reinstall Internet Explorer. To do so, see the appropriate section:
Install Outlook Express
Outlook Express is an Internet Explorer component that you can
install after Internet Explorer is installed by using the Add/Remove Programs
tool in Control Panel.
For information about how to add or remove
Internet Explorer components, please see the following article in the Microsoft
Knowledge Base:
171229
How to Add and Remove Internet Explorer Components
Install Internet Explorer
Reinstalling Internet Explorer restores Windows Messaging as a
mail service option. For information about Windows Messaging and installing
Internet Explorer, see the following articles in the Microsoft Knowledge Base:
158435
Windows Messaging Missing from Mail and News Options
170993
How to Install Internet Explorer 4.0