There are lots of ways to do this. In my view the best way is to download and burn a CD of Ubuntu Linux and install it on your computer - for those not wanting to do scary sounding things like repartitioning their hard drives you can use a lovely little thing on the CD called Wubi which can put the whole of Ubuntu Linux in just one file on your computer. This means that if you don't like it you can get rid of it completely very easily. It runs very nicely and won't interfere with Microsoft Windows at all. Ubuntu is a good choice as both The GIMP and Python are installed by default and ready to use from the moment you see the desktop.
Sadly, not everyone wants to try this, and for them I managed to find a good explanation of what you need to do here. I've summarised the important bit below:
What do I need to do to get Python scripts to work?After you have installed The GIMP with the other other bits and pieces, to install a Python plug-in on The GIMP:
You have to install Python (as of GIMP 2.6.4, both Python 2.5 and 2.6 are supported), PyCairo, PyGObject and PyGTK.
If you haven't installed The GIMP yet, install these files first.
If you installed GIMP before installing Python, PyCairo, PyGObject and
PyGTK, run the GIMP installer again to install the GIMP Python components.
- Shut down The GIMP
- Copy the plug-in files to ~/.gimp2.6/plug-ins (where ~ is %USERPROFILE% - probably in My Documents somewhere - do a search for a folder called gimp2.6)
- Restart The GIMP