I am on windows 7 and I am trying to install play framework.
I created the environment variable in system variables with
variable name:
I realized that it doesn't work if you have a space in your path to the play framework.
So instead of
C:\Folder with space\PlayFramework
try
C:\FolderWithoutSpace\PlayFramework
This fixed it for me, guess it has to do with the play batch file which doesn't handle paths with spaces correctly. Stumbled upon this question, when searching for a solution, so it might help some other folks.