I use this script for years and I`m very happy with it. Simply select a file or directory in Windows Explorer and copy it`s path to the clipboard directly from the context menu.
To install it, run a command shell as admin and call the script without an argument. After that it is installed and can be used from the context menu.
Grig Gheorghiu wrote on blogspot.com a howto for installing Python Scripts as Windows Services. It uses instsrv.exe and srvany.exe from the Win2K Ressource Kit.
The class I found on Activestate wraps most of the win32api functions for accessing a registry. It will read and write all win32 registry types, and will de/serialize python objects to registry keys when a string or integer representation is not possible: