If you use set TCL_LIBRARY=C:\Program Files\Python 3.5\tcl\tcl8.6
set the TCL_LIBRARY for current command session.So when you close your command prompt then it's not work.
So the fix is go to System -> Advance System Setting -> Environment Variables
and set variables for user
Variables name: TCL_LIBRARY
Variables value: C:\Program Files\Python 3.5\tcl\tcl8.6
Then click ok, your setting saved.Now close the current command prompt open new command prompt and try
C:\Program Files\Python 3.5\Lib\idlelib>python idle.py
it will work.
Thanks
For Linux users: