This tutorial will explain how to create system image backup for Windows 10 in same hard disk. Before you begin, make sure I am no responsible if you lose your data in the process. Follow carefully and you should be able to reset Windows 10 installation with disk/usb installation. While following this tutorial, you should have empty partition in your hard drive, not less than 15GB in size. Also make sure there is no write protection enabled to that partition slice. Hit WIN key+R and type diskmgmt.msc .

First, open ```Control Panel```

Open ```File History``` and look for ```System Image Backup```. Click it.

Click on ```Create a system image```

Select partition you would like to use. It should be attached to a drive path or network path

Next, you will be prompted to select which partition would you want to back up. You can select partition where your Windows installation is in and System Reserved.

Once you're done, to make sure your new system image is working, hold SHIFT and click on restart, you will be prompted to troubleshoot your PC. Choose Recover from System Image.

Leave a comment if you would like to see video demonstration of this tutorial.

Source: https://www.cnet.com/how-to/how-to-create-a-system-image-in-windows-10/