Need help on getting started with google app engine(PYTHON 2.7)

I've installed GAE in my computer(windows 7 64-bit). But whenever I click run on the program it doesn't work, and when I use the command line using dev_appserver.py this happens "dev_appserver.py is not recognized as an internal or external command, operable program or batch file". What should I do?

edit1: Here's the log error when I'm using the program.

edit2: Here's my full python path

C:\Python27\Lib\site-packages\PyQt4;c:\users\jansen\appdata\local\enthought\canopy32\user\scripts;C:\Users\jansen\AppData\Local\Enthought\Canopy32\User;C:\Users\jansen\AppData\Local\Enthought\Canopy32\User\Scripts;C:\Python27;C:\Python27\DLLs;C:\Python27\Scripts;C:\Python27\Lib\site-packages\vtk;C:\Python27\gnuplot\binary;C:\Python27\Lib\site-packages\osgeo;C:\Program Files (x86)\pythonxy\SciTE-3.5.1-4;C:\Program Files (x86)\pythonxy\console;C:\Program Files (x86)\pythonxy\swig;C:\Program Files (x86)\pythonxy\gettext\bin;C:\Program Files (x86)\Google\google_appengine\