More likely than gorath's scenario is that your laptop has both an Intel integrated HD-x000 graphics chip, and the nVidia GTX770m, and for some reason the Intel chip is what's being detected. To see if this is the case, run the ME2 config utility "C:\Program Files (x86)\Origin Games\Mass Effect 2\Binaries\MassEffect2Config.exe".
And if it is, look in the owner's manual for how to disable the on-board video completely.
I know you said you turned-off gpu switching, but that was in nVidia's control panel. Your rig (and ME2) may not pay attention to that...