Outlook is a marvelous piece of software that not only takes care of emails and contacts, but also manages to-do lists and various appointments and tasks.

However, if you don't do some basic maintenance on your personal folders files (*.pst), you'll experience a significant degradation in performance even if you don't have virus or other issues on your computer.

In order to keep your Outlook running optimally, you should do the following regularly:

• Compact the pst and ost files. (Compacting the ost files isn't applicable for people who aren't using an MS Exchange server.)
• Scan the pst and ost for errors and repair them. (Again, the instructions on ost files aren't applicable for people who aren't using an MS Exchange server.)

Hope this helps!