default import path

[Peter]

<newbie question>
How can I edit the default import path for Python under Windows?

I want to use the piddle module.  So far, I've copied the unzipped contents
of the zip file to c:\prog~1\python\lib\site-packages, but how do I set it
so this is automatically on the python path?

(I don't want to have to manually add that directory every time.)

TIA

Peter