How to Switch From Windows 10’s Insider Preview Back to Stable (Without Reinstalling)
 

When you sign up for Insider Preview builds, Windows warns that you “may” need to reinstall Windows to get back to the stable version of Windows. But this is a worst case scenario, and there are other ways to get off the Insider Preview track.

http://www.howtogeek.com/274780/how-...-reinstalling/