Windows 10 already includes ways to clear out applications and data to repair misbehaving systems or prepare them to be sold, courtesy of the Refresh and Reset features added in Windows 8. Microsoft is now adding a third option: a new refresh tool.
Currently available only for Windows Insiders, the new tool fetches a copy of Windows online and performs a clean installation. The only option is whether or not you want to preserve your personal data. Any other software that's installed will be blown away, including the various applications and utilities that OEMs continue to bundle with their systems.
The tool is currently in preview and has some quirks; it installs a preview build from the fast track, but Microsoft notes that the new tool can sometimes install a version older than the one currently installed. When this kind of version mismatch occurs, the option to preserve your files is removed.