I use Oracle under UNIX, but not under Windows. So, my response may not be of much help. Under UNIX, the file /var/opt/oracle/oratab has a line of the form
$ORACLE_SID:$ORACLE_HOME:<N|Y>, where the first and the second fields are the system identifier and home
directory of the database respectively. The third field indicates to the ‘dbstart’ utility that the database should, “Y”, or should not, “N”, be brought up at system boot time.
You may ask a Windows expert about a comparable file in Windows.