Outlook Express probably won't work because Internet Explorer is corrupted. If you repair IE6 this may also repair Outlook Express as both are "intertwined"

Method 1: Microsoft Internet Explorer 6.x Repair for Windows XP
  • From the Start menu, select Run.
  • In the Open field, type sfc /scannow (Note: There is a space between sfc and /scannow)
  • Select the OK button.
  • Follow the prompts throughout the System File Checker process.
  • Reboot the computer when System File Checker completes.
Method 2: Microsoft Internet Explorer 6.x Repair for Windows XP
  • From the Start menu, select Search, select All Files and Folders.
  • Select More Advanced Options and place a checkmark beside Search Hidden Files and Folders option.
  • Ensure that Search System Folders and Search Subfolders are also checked.
  • In the All or Part of the File Name box, type ie.inf
  • In the Look In drop down menu, select C: or the letter of the hard drive
  • Click the Search button.
  • In the search results pane, find the ie.inf file located in Windows\Inf folder.
  • Right click the ie.inf file and click Install on the context menu.
  • Reboot the computer when the file copy process is complete.