You will need to select a location to save your back up file.
Open the system settings screen by clicking on the Tools menu. Select System Setup, then System Settings.
Expand Setup by clicking on the + sign.
Enter the desired location for your backup files on the Backup Directory line.
On the main menu, select Tools, then select Maintenance, now click on Back Up.
Choose the location of your backup in the window that pops up and press [OK].
In your backup directory check for your backup file (MPNET.BAK).
This should be copied on to an external device (DVD, CD, Portable drive or USB Stick