kKaltUuso ehm... http://i.imgur.com/QXIrZlW.png
What is going on here?
Edit: http://i.imgur.com/TiclVvH.png
Seems that if you have a second monitor enabled you automagically switch to the max supported hertz for BOTH of them.
Hey, I have 2 monitors too, if you use the control panel setup I have in the OP then you should be able to use 144hz on one and 60 on the other, make sure to select your 144hz monitor as your main monitor and choose the "extend these displays" option.