Registry Fun (Working With Hive Files)
Sometimes it is necessary to export/import data from or into the registry for some sort of additional processing. To this end, often regedit is used to create .REG files, which store a human-readable text interpretation of the registry content. .REG files can be edited easily with any capable text editor (even Notepad), and thus are a common way of making a collection of settings available to others. By the way, importing a .REG file’s data silently is done with the following command:
Windows Internals