Tensorflow just released windows support. I installed the gpu version and CUDA 8.0 and python 3.5. However, after I import the tensorflow I got the following error:
Also make sure that there is no additional cudnn64_5.dll (of the wrong version) sitting in another path.
So if you put the DLL in ...\CUDA\v8.0\bin in the past, remember that you did and do not put a newer version into ...\CuDNN\v5.1\bin without removing the old one from the other directory.