Thank you for the trick of command line.
Today I've formatted my drive C:\, restore a previous GHO (ghost) file of my system to my PC (and come back to my system of 1 year ago). Then I installed a fresh copy of Cocos Creator, NDK, SDK, Python, JavaSDK, ... I can't remember all.
And of course, things worked well. But I'll consider your suggestion the next time this problem occurs.
Thank you anyway!