| Windows 8.1 lets you make a system image backup from
Control panel | File history | System Image Backup
If you connect a USB mass storage device like a 2.5" portable hard drive, it will go smoothly.
If you connect a USB flash stick, it will complain that the drive is not a valid backup location.
You can trick it by using a networked location on the usb stick:
- Create a directory on the usb stick
- Right-click and setup as a share with everyone
- Select the directory from the networked locations from within the System Image Backup dialog box.