Lines beginning with "PS" are commands to be typed into Windows Powershell. Don't type the "PS" part.
Download 2.7.4: http://www.python.org/download/releases/2.7.4/
I used 64bit, instructions differ for 32.
Go to Control Panel > System > Advanced system settings > Environment Variables Scroll down to Path in the bottom list, edit Path and append ";C:\Python27;C:\Python27\Scripts" to its value (very important to do this verbatim, leaving off the leading semicolon will break everything)
2nd directory ("Scripts") is to get easy_install on the path
Run ez_setup.py script downloaded from here: https://pypi.python.org/pypi/setuptools
It was at http://peak.telecommunity.com/dist/ez_setup.py when I visited last.
PS python ez_setup.py
Install pip
PS easy_install pip
Install pymarc
PS pip install pymarc
You're done.
To execute scripts, just run
PS python script_name.py