It worked fine beforeLikely because the monitor is connected to the igpu. Change the plug to the gpu.
16 GB Ram 1600 mhz Gtx 1060 3gb i5 4670System specs please? Discrete card installed?
Would outdated drivers be the issue? or would it be it the monitor settingsThe only way the igpu would be used is if there is a monitor in it and windows is set for that monitor to be the main.