MS Outlook

one of my end-users has managed to changed the default e-mail client from MS Outlook to MS Outlook Express and now that she wants to e-mail within MS Word MS Outlook Express opens first (MS Outlook express configured to received her personal e-mail messages from Hotmail) and if you cancelled when prompted for MS Outlook Express username and password or Hotmail info, MS Word doesn’t give the opportunity to use another e-mail client. is there a way to change the default back to MS Outlook? p/s i already changed Internet Explorer’s setting to MS Outlook, but MS Outlook Express keeps popping up.