For diverse additional software (PIL, TextindexNG, MySQL-Adapter etc.) besides Unix also Windows installation programmes exist; these usually request a registry entry for localisation of the Python interpreter. You yourself can easily generate a correspondent reg-file with a Python script.
Diverse extensions of the Zope system are communicating via a Python interface with external programmes. Exemplified for a MySQL installation under Windows98 the registration process will be made clear; the already with Zope installed Python version 2.1 from directory $zopehome/bin shall be applied:
Identifying the installed Python-interpreter: with the Zope installation the Python-interpeter is installed, but the installation is doing without a registry entry. However for installation of more Python programmes this entry is required; so that the installer can find the correct Python version (like in the screenshot above) a seperate registry is needed in advance.