Windows7 has it's own, perfectly adequate built-in backup program, found in Control Panel > Backup and restore, with which you can create a system image, backup individual files, and set up a regular schedule. It is vastly improved over efforts in previous operating systems. Suggest you ditch Seagate and have a look at this. Don't forget to create a rescue (boot) disk.
OnePlus 5T review: Hands-on