tensorflow gpu install window error : self_check.py...ImportError: Could not find 'cudnn64_6.dll...

hmm......I have taken for about 5 hours for solve this problem....

error is like that:

Traceback (most recent call last):
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\site-packages\tensorflow\python\platform\self_check.py", line 87, in preload_check
    ctypes.WinDLL(build_info.cudnn_dll_name)
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\ctypes\__init__.py", line 348, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: [WinError 126] 지정된 모듈을 찾을 수 없습니다
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\site-packages\tensorflow\__init__.py", line 24, in <module>
    from tensorflow.python import *
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\site-packages\tensorflow\python\__init__.py", line 49, in <module>
    from tensorflow.python import pywrap_tensorflow
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\site-packages\tensorflow\python\pywrap_tensorflow.py", line 30, in <module>
    self_check.preload_check()
  File "C:\Users\mare\Anaconda3\envs\mare4\lib\site-packages\tensorflow\python\platform\self_check.py", line 97, in preload_check
    % (build_info.cudnn_dll_name, build_info.cudnn_version_number))
ImportError: Could not find 'cudnn64_6.dll'. TensorFlow requires that this DLL be installed in a directory that is named in your %PATH% environment variable. Note that installing cuDNN is a separate step from installing CUDA, and this DLL is often found in a different directory from the CUDA DLLs. You may install the necessary DLL by downloading cuDNN 6 from this URL: https://developer.nvidia.com/cudnn

In conclusion..
just use cudnn 6.0, that is Download cuDNN v6.0 (April 27, 2017), for CUDA 8.0

I have tried many time
cuda 9.1 + cudnn 7.x
cuda 8.0 + cudnn 7.x
...
but I never successed

tensorflow official site recommend
cuda 8.0 + cudnn 6.1
https://www.tensorflow.org/install/install_windows
I just ignore this mention, because you know I thought the document is outdated.



This is simple tutorial for install tensorflow-gpu in window.

1. install anaconda.

conda create -n tensorflow python=3.5 

2. install cuda 8.0 and cudnn 6.x

move cudnn header, lib and dll to cuda 8.0 folder
http://docs.nvidia.com/deeplearning/sdk/cudnn-install/index.html#installwindows

3. install tensorflow-gpu

pip install --ignore-installed --upgrade tensorflow-gpu 

4. check tensorflow-gpu

>>> import tensorflow as tf
>>> tf.test.is_built_with_cuda()
Ture