Outlook XP is slow !!

I've been using Office XP since right about when it first came out. In the past few weeks it has become extremely slow. When I switch from one message to another it takes forever to show up in the preview pane. This had never happened before. My OS is Microsoft XP Professional. Here's what I've tried:

Reinstall Office XP
Repair Office
Clean out my folders (inbox, sent, etc)

The only thing I have not tried is uninstalling and reinstalling, but with product activation I'm kind of wary of doing this. My PC:
PIII 500
256MB RAM
ATI PRO AGP/32MB
40G HD

Any tips or suggestions? Thanks!

 

Outlook

1. Try compacting the .pst file
2. You don't say how big your .pst file is but you might need to archive some entries.
3. I believe MS still supplies the inbox repair tool.

Some suggestions I could think of.