On Windows, TensorFlow reports either or both of the following errors after executing an import tensorflow statement:
No module named \"_pyw
For each Tensorflow's version, it requires different version of CuDnn. On www.tensorflow.org, they did not mentioned about that in installation guide!
My case use tensorflow version 1.3 which uses cuDNN 6. https://github.com/tensorflow/tensorflow/releases.
Please check your tensorfow version and cuDNN version if they are match together.
And please set path environment for cuDNN, if it still does not work, please check the answer from @Chris Han.