Thank you Mathwiz.
However, i would like to use python 3.5 through the Windows Command line, in order to easily upgrade pip, install jupyter, tensorflow, keras, e.t.c. The problem with Python command prompt, in all python versions, is that it routinely pops Syntax Error: Invalid Syntax. This makes Python Command Prompt almost unusable.
P.S. I already tried to change system variables > Path, but then the command Python is not recognised at all. Previously, i tried to use Anaconda, but to no avail· it only recognises python 3.4