Hereare the instructions on how to reset Windows 10 to factory default settings:
StartWindows 10 and on the login screen, click on the Power button. Hold down theShift key and click restart. You will see the following screen. Make sure youhold the Shift key down when Windows is restarting and don’t release it untilyou see the first screen with the troubleshoot option. Click Troubleshoot.
On the next screen, click the Reset PC button.
You can choose to reset the PC and keep all your files and apps, or you can get aclean Windows 10. In this situation, you will want to select: Remove everything.