a = mx.nd.ones((3,4), ctx=mx.gpu())
this line can run on windows with mxnet 1.2.0 without any problem.
But it can NOT run on windows with mxnet 1.2.1. The program just quit without any response.
I guess the mxnet 1.2.1 does NOT support GPU on window. Both cuda 9.0 and cuda 9.2 are tested.