Backing up Files and your system, Windows 8 and 8.1

After you have all your apps loaded and running on Windows 8 or 8.1, you can make an "image" of all that on an external drive, so you can recover the entire thing.

According to Microsoft, this is what an image is:

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 WindowsBackup 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. For more information about setting up Windows Backup, see Back up your files.

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.

So you should also start a process running that backs up your personal files.  The best way to do that is to do an incremental backup, where you first get a complete backup, and then, whenever a file changes, that change is backed up.  You might set the backup so only so many revisions of a file are saved.  The oldest gets change gets deleted.

References:

• General reference on how to create a backup image, file incremental backup or full backup, etc.  Pretty much all you need to know.
• Specific reference on creating an image for Windows 8