Hi Mike I assume you mean the 'customise' option in the NVidia control panel ! Tried that, did not work. Tried everything that people suggested without any success. This is the only way I could get 3840 x 2160 60Hz.
OK this is fixed ! You have to run NVidia driver 353.62 ! This allows me to run at 3840 x 2160 and I get 60Hz. Obviously later drivers do not work correctly in Windows 10. I found other people with same problem and this has fixed it.
Just tried updating the Nvidia driver to latest version and it locked the refresh rate to 30Hz in this pre November version. I rolled back the driver to 353.62 ! So now I will update Win10 to 1511 and then install the 353.62 legacy driver and see if this works.
Yeh thought of that but it really is last resort ! Will search a little longer and see if I can find anything. Thanx for the help kemical, appreciate it.