Which Windows Registry root key includes subkeys that define settings for all users on the computer?

• A. HKCU
• B. USERS
• C. HKLM
• D. CLASSES_ROOT

Answer: (C)

Windows Registry organizes settings by scope: machine-wide versus per-user. The root key that defines settings for all users on the computer is the one that holds configuration applicable to the entire machine. That is HKEY_LOCAL_MACHINE, which includes subkeys for hardware, services, software installed for all users, and system-wide policies.

In contrast, the current user root key stores preferences for the user who is currently logged in, not for everyone. The classes root area deals with file type associations and COM class registrations, not general machine-wide configuration. The users root area holds the per-user hives for all user profiles, but the machine-wide settings affecting every account live under the machine-wide root.