After a bit of struggling with the upgrade on two Windows XP machines, I think I've sorted it out; if you don't have Python installed in C:\Python then the easy_install scripts don't get installed properly, and the subsequent command dies with the 'No script named easy_install.py' error.
After looking at the OS X instructions I figured that I had to run the installer as:
python ez_setup.py --script-dir C:\Python24\Scripts -U setuptools and then everything worked fine. Cheers, Julian.
