A python script that will extract the SAM, SYSTEM, and SECURITY registry hive files to C:\ for easy extraction.
Simply run this python script and the 3 registry hive files will be stored in the C:\ directory. I typically compile the python script to an executable in case the target machine doesn't have python installed.
Note: This must be ran by a user with administrative privileges.
I have tested this on Windows 7 and Windows 10.