A system image is an exact copy of a drive. By default, a system image includes the drives required for Windows to run. It also includes Windows and your system settings, programs, and files. You can use a system image to restore the contents of your computer if your hard disk or computer ever stops working. When you restore your computer from a system image, it's a complete restoration—you can't choose individual items to restore, and all of your current programs, system settings, and files are replaced with the contents of the system image.
Although this type of backup includes your personal files, we recommend that you back up your files regularly using Windows Backup so that you can restore individual files and folders as needed. When you set up Windows Backup, you can let Windows choose what to back up, which will include a system image, or you can select the items that you want to back up and whether you want to include a system image.
If your computer contains several drives or partitions, you can create a system image that includes all of them by following the steps in Back up your programs, system settings, and files.