Add blurb about executable scripts on Windows. #760657.
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
index 1ba14d9..5a3431d 100644
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -166,6 +166,12 @@
 
    $ chmod +x myscript.py
 
+On Windows systems, there is no notion of an "executable mode".  The Python
+installer automatically associates ``.py`` files with ``python.exe`` so that
+a double-click on a Python file will run it as a script.  The extension can
+also be ``.pyw``, in that case, the console window that normally appears is
+suppressed.
+
 
 Source Code Encoding
 --------------------