+-key_handle-+   +-subkeyname-+

Replaces the backup file of a key or subkey with a new file. Key must be an immediate descendant of HKEY_LOCAL_MACHINE or HKEY_USERS. If key_handle is omitted, the backup file of CURRENT_KEY is replaced. The values in the new file become active when the system is restarted. If subkeyname is omitted, the key and all its subkeys will be replaced.