[MichiganMat]

The "registry" is the central library of information for all the apps, drivers, and etc on your system. When one app wants to find another to exchange information or launch it, it goes to the registry. When a device is added to the system and a driver needs to be loaded, it goes to the registry. When an app wants to save its position when it closes, it saves it to the registry.

In short, its the heart of the beast, and its all in one, easily corruptable, location. Mac uses a slightly different approach by using a registry only for devices and then giving individual prefs files to each application on the system. Much safer, simpler, etc etc etc.