You can simply burn it to a CD when Outlook is closed. For step-by-step
backup and restore instructions see;
http://www.howto-outlook.com/howto/backupandrestore.htm
Note that you cannot read pst-files directly from a read-only medium such as
a CD. If you want to do this for archiving purposes, I can highly recommend
HTML Email Archiver from MAPILab. You can then burn that archive with the
original pst-file to the CD (or even leave out the pst-file) so you can
still read and search through your messages directly from the CD and only
restore your pst-file when it is really necessary.
For more details see;
http://addins.howto-outlook.com/mapilab_archiver
If you decide to order use 4PM76A8 to get a discount.