Reset: clean install Windows 10 the easy way
The normal upgrade process in Windows 10 takes old files, settings, and programs from a previous system to a new one. You can, however, refresh your computer completely by carrying out a clean install. However, the activation process can be trickier.

A clean install can come in handy if you want to dodge the ton of bloatware that manufacturers install. It is also necessary when you have replaced a hard drive.
By far the easiest way to do a clean install is to use Windows 10’s Reset function. This differs from the Windows 8 Reset function as that feature used a recovery image from manufacturers that was customised for their software. Sure, that would include the specific drivers from them, but this also included bloatware and in some cases (*cough* Lenovo) undesirable software such as Superfish.
Windows 10 offers a system that rebuilds the operating system without the need for a separate recovery image, cleaning up the OS but keeping the latest files – so you don’t have to run Windows Update directly after a reset.
Microsoft says this resetting brings “Windows devices back to a pristine state” with only Windows files installed.

To reset your Windows 10 PC, open the Settings app, choose Update & security, choose Recovery, and click the “Get started” button under Reset this PC. Choose “Remove everything.” This will wipe all your files, so be sure you have backups.