python - pyrcc4 command not recognized as internal or external command?

The question has already been asked as 'pyrcc4' is not recognized as an internal or external command? but the answers did not fit my own trouble.

I am trying to create a plug-in. I followed the Qgis Cookbook and when I start the OSGeoW4 shell I type the following code (xxx is the name of the Beta plugin) :

cd c:\Users\Guillaume\.qgis2\python\plugins\xxx

then make

which doesn't work nor

pyrcc4 -o resources_rc.py resources.qrc

They are not recognized as internal or external command.

So little research lead me to look after the /bin from qgis and I found pyrcc4.exe but no pyrcc4.bat

I have two python version (2.7) one from the ArcGIS package which is working nicely as a shell on pyzo python interpreter, and one downloaded from the python.org.

I'm working with QGIS 2.18.23