Is this what's going on?
The person who had the computer before you had Outlook Express setup with his email. Does he need to get his data from OL to put on his new computer? If that's the case, see Microsoft article 270670
that explains how to back up and recover Outlook Express data. You can use this method to back up the data, move it to the new computer, and recover it.
You just got a used computer and need to add your own email account to Outlook Express? If so, see Microsoft Article 171163
to add your account.