Passport will not back-up

My Passport Essentials will back- up files changes that are occuring when hooked up to my laptop but will not back-up files changes that were made on my laptop prior to connecting my Passport to my laptop.

Please help

Hello,

WD Smartware software has been designed to backup your files automatically, if you make changes on your computer while the passport is not plugged in, then when you plug in the drive it should update the backup automatically. In order to make sure the backup software is working properly I will recommend that you verify if you have the latest version of the software installed, 1.6.5 for Windows and 1.3.4 for Mac.