As long as you feel like you have al the messages you expect to have you
should be able to delete the .pst file that Outlook is NOT using.
Depending on your version of Outlook, you will need to determine whic .pst
file Outlook is using currently.
Once you have determined which file Outlook is using (and that you have al
your expected messages!) then you can delete the other .pst file.
To determine which file Outlook is using for Outlook XP-2003 go to
Tools>>Options>>Mail Setup>>Data Files
When you open this box it should indicate the directory path for any .pst
files Outlook uses under the "filename" column. Nest to this column is a
column named "comment"..................the one that has "Mail Delivery
Location" is the .pst files that contains the messages in your current
personal folders--Inbox, Sent Items, etc....
I would think that deleting the .pst file that IS NOT being used for mail
delivery would not be problematic, HOWEVER, if you think there is a
possibility that you are missing some "must have" e-mails and that they may
be in the backup file, then there is no harm in leaving boith .pst files.
Only if the files were extremely large (>500MB) should you think about
deleting the other file if you think there may be needed messages in that
..pst file.
Hope this helps.