Remind the users of VS version for windows build.

README.md

@@ -34,7 +34,7 @@ export PYTHONPATH=${SYNOPSYS_CAFFE_HOME}/python:${PYTHONPATH}
 
 ### Windows   
 A simple guide:
-1. Download the Visual Studio 2015 Update 3. Choose to install the support for visual C++ instead of applying the default settings.
+1. Download the **Visual Studio 2015 Update 3** (Do not use the VS 2017, it is not supported!). Choose to install the support for visual C++ instead of applying the default settings.
 2. Install the CMake 3.4 or higher. Install Python 2.7 or 3.5. Add cmake.exe and python.exe to your PATH.
 3. After installing the Python, please open a `cmd` prompt and use `pip install numpy` to install the **numpy** package.  
 4. Checkout the Synopsys Caffe **master** branch for build. The windows branch is deprecated, please do not use it. We use `C:\Projects` as the current folder for the following instructions.