To back up Windows, you need to make an image of the C partition.
And the System Reserved partition, if you have one.
You recover Windows by restoring those images. Usually it works, sometimes it doesn't.
The most commonly recommended program to do it is Macrium Reflect Free Edition.
Imaging with free Macrium
Back up your personal stuff--photos, data, etc, without using an image, just as you apparently are doing now.