I would say the Nvidia Control panel issue would be fixed by reinstalling the Nvidia Drivers.
I've been fight with the Nvidia adapter graphics since forever and either the video is slower than Intel for when it takes over or it will not run when it setup in the Control panel. Hence Lot Of Luck also = LOL (could not resist it)
Sometimes we just have to chuckle at the lack of ingenuity of the engineers. Not tested until perfect!!
T520 Model 4239 Intel(R) Core(TM) i7-2860QM CPU @ 2.50GHz Intel Sandy Bridge & Nvidia NVS 4200M graphics Intel N 6300 Wi-Fi adapter Windows 7 Home Prem - 64bit w/8GB DDR3