Uninstall / Reinstall OE and IE from the registry

How to Reinstall or Repair Internet Explorer and Outlook Express in Windows XP

1. While you are logged on as an administrator, click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate the appropriate registry subkey, right-click the IsInstalled (REG_DWORD) value, and then click Modify.

To reinstall only the Internet Explorer 6 browser component on Windows XP, use the following registry key:
HKEY_LOCAL_MACHINE >> SOFTWARE >> Microsoft >> Active Setup >> Installed Components >> {89820200-ECBD-11cf-8B85-00AA005B4383}

To reinstall only Outlook Express 6 on Windows XP, use the following registry key:
HKEY_LOCAL_MACHINE >> SOFTWARE >> Microsoft >> Active Setup >> Installed Components >> {44BBA840-CC51-11CF-AAFA-00AA00B6015C}
4. Change the value data from 1 to 0, and then click OK (To Uninstall OE or IE) OR Change the value data from 0 to 1, and then click OK (To Reinstall OE or IE)

5. Quit Registry Editor, and then restart the computer