What was the previous GPU? Did you cleanly uninstall all of the old Drivers?
Yes I did my previous GPU was a AMD Radeon R5 235
It's always tricky upgrading from AMD to nVidia.
Check your file systems and ensure that all folders including "AMD" or "ATI" are gone.
This is a good tool for the job - http://www.guru3d.com/content-page/guru3d-driver-sweeper.html
Also, do you have the most up to date driver for your 960?