Thanks for downloading treelib. To install it, make sure you have Python 2.6 or greater installed. Then run this command from the command prompt: python setup.py install If you're upgrading from a previous version, you need to remove it first. AS AN ALTERNATIVE, you can just copy the entire "treelib" directory to Python's site-packages directory, which is located wherever your Python installation lives. Some places you might check are: /usr/lib/python2.7/site-packages (Unix, Python 2.7) /usr/lib/python2.6/site-packages (Unix, Python 2.6) C:\\PYTHON\site-packages (Windows)