A few things come to mind:
Have you installed the latest service release of Rhino x64? You should be on version 5 service release 13.
A word of caution: don’t update win10 just yet. The next version is the Creators Update, which seems problematic: Windows 10 Creators Update - REVISED - Fixed with V5 SR14
Lastly, have you tried the WIP version of Rhino-6? Click the link which is above the forum to get it. See if you have the same problem there (they can be installed side-by-side).