How does one reinstall Internet Explorer and Outlook Express?

The first step is to go to Control Panel > Add/Remove Programs and see if Microsoft Internet Explorer is listed.  If you find it there, select it and click the Add/Remove button.  You should then be given the option to either uninstall or repair.  Choose "Repair" the first time to see if that corrects your problem.  Remember when downloading and installing IE/OE it is imperative that your anti-virus application be disabled.

This article seems to work for other Operating Systems than just Windows XP:
How to Reinstall or Repair Internet Explorer and Outlook Express [Q318378]
http://support.microsoft.com/default.aspx?scid=KB;EN-US;318378