outlook express inbox problems

Your email DATA is still there

PAUL, do not panic, the data should still be on your hard drive.
Are you using Mac OS X? If so, what is your version? (10.3.3?)
Since you are using Outlook instead of Entourage, I take it you do not have MS Office X. Correct? If so, your data folders will be different from mine.
Are you familiar with where your system stores your email data?
Have you checked your own User's Document folder?

When was the last time you backed up your data? (I'm not so much expecting an answer, just encouraging you to do so, soon!)

You may have inadvertently clicked on something (like "Hide Folders" at the top) that changed the folders in the left to where you can't see them, or the column)
If you have a left column, You need to click on the triangle beside "On My Computer" to open it up.
tell us more...
Even if you reinstall Outlook, it should have no effect on your data because they are not kept in the same place, which is a safeguard.