This is probably another Optimus problem.
Can you specify if, you have this issue all the time or in specific program? Or you mean the windows isn't running in the nvidia card? It's suppose to be like that and you can't change it (yeah that was the bad thing of optimus).
If you can't activate the nvidia card, try this way. Go to nvidia control panel and then, click 'Manage 3D settings' on the left-side tab of your nvidia control panel window. There you should be in the 'Global Settings' tab, if no go there.
Then in there, you'll see 'Preferred graphics processor' area, below that, you can see that you can choose between GPUs and you are there, just change it
. Click apply and if you don't have issue, games will run to the nvidia GPU
.
Hope this helps
. Good luck
.