Registry Key Info

Typical key structure for the registry is:

Folder / predefined key	Description
HKey_CURRENT_USER	Contains root config regarding the user who is currently logged on. This directory can consist of folder, screen color and Control Panel settings. (HKCU)
HKEY_USERS	Contains all actively loaded user profiles
HKEY_LOCAL_MACHINE	Contains config information particular to the computer (for any user). (HKLM)
HKEY_CLASSES_ROOT	Subkey of HKLM\Software. Information stored here makes that the correct program association occurs when you open a file through Windows Explorer. Sometimes abbreviated as HKCR. HKLM\Software\Classes contains default settings for applications across the system. HKCU\Software\Classes contains config information specific to that users profile. If you are writing values to a key under HKCR, and the key has a pre-existing value within HKCU\Software\Classes, the system will store the information there instead of under HKEY_LOCAL_MACHINE\Software\Classes.
HKEY_CURRENT_CONFIG	Contains information about the hardware profile that is used by the local computer at system startup.