Oracle DataBase Server 12.1 installation on Windows 2008 Server]: Enable ARCHIVELOG MODE

sqlplus / as sysdba

SQL> select log_mode from v$database;

LOG_MODE
------------
NOARCHIVELOG

SQL> shutdown immediate;
SQL> startup mount exclusive;
SQL> alter database archivelog;
SQL> alter database open;

SQL> select log_mode from v$database;

LOG_MODE
------------------------------------
ARCHIVELOG

SQL> ARCHIVE LOG LIST

Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     30
Next log sequence to archive   32
Current log sequence           32

SQL> quit