I just bought a refurbished Lenovo y50 in the mail with a GTx 860 2gb card.
I ran some games to test it and everything worked fine. After the test, I updated my drivers to the latest version from NVIdia's website and whenever I try to run anything with the updated drivers I get a "your display drivers are not working" and my program freezes. My drivers just stop working completely when I update them.
When I uninstall the drivers and reinstall the 2014 version, everything works fine. I can even run games on Ultra settings. But then when I try to update them again, same problem.