I cannot even click on the Video rendering and playback drop down menu as it is greyed out.
I have a GeForce GTX 660 2GB card which should be supported as it has enough memory. I am on Windows 7.
Would really appreciate if someone has a solution how to enable Mercury Playback Engine in this situation.
Managed to fix the problem by downloading and installing the GeForce CUDA drivers as well as updating graphics card firmware.
The Mercury Playback engine enabled itself in premiere after the updates.