If you think that your Outlook Express 5 installation on Windows 2000 is corrupted, you can reinstall it:
1. Mount the Windows 2000 CD-ROM.
2. Exit all instances of Outlook Express.
3. Open My Computer.
4. On the Tools menu, press Folder Options.
5. On the View tab, select Show hidden files and folders and clear the Hide file extensions for known file types box.
6. Press OK.
7. Right-click %SystemRoot%\inf\msoe50.inf and press Install.