What program did you use to backup the files and did you do a complete drive image? My point is that if you did a complete drive image then you should be able to restore the image from the backup drive. 
Hello,  I recently had to backup my files to a Seagate external drive. I am wondering what program Dell uses so I can  view the backup files on the Seagate. Seagate techs can’t help me. Prior to the backup and restore. I was running Win 10 on my Inspiron 17R, I now have Win 8.1. I’m also trying to install Win 10, having no luck. The unfortunate part is I have many years of grandkids photos, camping. Thanks!!
Dell Backup and Recovery File Recovery