First, run a backup. Click on File, Backup Database.
Second, Click on File, Restore Database. In the pop up window that appears. Click on Find, look in the Windows (C:), ProgramData (this may be a hidden folder), CSK2013 or PSK2013 or SSK2013 (depending on what program you have), Backup. Now you can look through the backups MyPSK_2016_08_15_1345.sk5 or PSK_2016_08_15_1345.sk5
Backups will start with MyPSK or PSK depending on if you created the backup or the Sidekick automatically did the backup for you. Then they will have the date created starting with year, month, day of month, finally time (24 hour / military), and ending with sk5