Where did OUTLOOK go?

I setup a new XP for a user with Outlook Express then decided that I had to install OUTLOOK in order to import a .pst file from another computer. User likes Outlook Express but on her old computer I used Outlook to create a .pst file. On the new computer I can’t find OUTLOOK to setup a new account. Where did it go and how can I set it up again? OR …. how can I import messages from a .pst file into Outlook Express?