The HKEY_LOCAL_MACHINE\Security key contains security information for the local computer, including user rights, password policy, and the membership of local groups, as set in User Manager.
The subkey HKEY_LOCAL_MACHINE\Security\SAM is mapped to HKEY_LOCAL_MACHINE\SAM, so changes made in one automatically appear in the other.
If you want to change global group membership or other security-related items, use User Manager or User Manager for Domains.
Caution The information in this database is in binary format and should not be changed by using Registry Editor. Errors in this database may prevent users from being able to log on to the computer.