There is some documentation on the subject at: http://docs.python.org/using/windows.html
In general, there are several options in maintaining separate environments: 1) Create a separate user for each environment. This allows you to keep things such as Path and file associations so that you are selecting a certain install whenever you are logged in as that user. This may NOT be an option on Vista though. The Python installer will tell you whether you can install for only the current user. 2) Use batch scripts to setup your PATH and PYTHONPATH. This will not solve the file association problem, but you can probably set up your "SEND TO" folder to handle the different versions. 3) Use something like virtualenv. I'm using option 2). A couple more hints: if you are using a windows installer for a third- party lib, (like wxpython), the installer will look in the registry for a matching python installation. If there isn't one, it shouldn't be a problem, just install it where it needs to go. (in the appropriate Python folder). You can also use the repair option for the python installer to get the registry set up for a particular install. For example, if you installed Python 3, but want to then use associations with 2.6, just use repair with the 2.6 installer. (Not sure what else repair does though) Finally, you can use the --prefix option to setup.py to get installs to go where you want on win. -- http://mail.python.org/mailman/listinfo/python-list
