This option in Windows-10 is good if you want to restore default Windows 10 settings or if you are having trouble with Windows 10 and need to reinstall it by performing a custom installation of Windows 10 .
For all cases for example system crash, back up any files and settings you want to keep so that you can restore them after the installation.
Please start the Recovery Options in Windows 10, for example via Windows-Logo + I Keyboard Shortcut and select Update & Security select Recovery and Reset this PC. (... see Image-1 Arrow 1 to 4)
and choose the reset options (... see Image-2 Arrow-1) that is it :-)
See also: . Clean Installation of the Windows 10 || install Windows-10 without Microsoft Account || Windows 10 no Product Key
FAQ 123: Updated on: October 4th 2015 21:30