However before you go exploring Windows 10 it’s time to make that final image backup. So reboot the computer, click on the Windows 7 icon to load Windows 7, then launch your backup software and create a backup of the entire drive.
After completing the image backup your USB drive should have 3 folders and look similar to that shown below.
Note: Should you need to restore Windows 7 or the Windows 10 Technical Preview you can just select the partition that you want to restore, no need to restore the entire drive.
If you are using Windows 7 for most of your work and just exploring Windows 10 then you should consider creating a “Scheduled” daily backup of the Windows 7 partition, or you can include both Windows 7 and 10 partitions if you like and have the available space on your external USB drive. Pick a time when you know the PC will be on but you’re not using it, Dinner time for example.