Can a python script persistently change a Windows environment variable? (elegantly)

Question

Following on from my previous question, is it possible to make a Python script which persistently changes a Windows environment variable?

Changes to os.environ do n

Answer 1

Windows sets Environment variables from values stored in the Registry for each process independently.

However, there is a tool in the Windows XP Service Pack 2 Support Tools named setx.exe that allows you to change global Environment variables from the command line.