How to Shutdown Oracle Instance on Windows Platform?

Oracle 9.2, Windows 2000

Shutdown oracle instance through SQL*Plus is always the safe way.
If you want to shutdown oracle instance through oracle service on windows platform, make sure the following parameters are set in the Registry.

Under HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\HOMEX\:

ORA_SID_SHUTDOWN = TRUE|FALSE - Set this to TRUE to enable the proper shutdown of the database
ORA_SID_SHUTDOWN_TIMEOUT = Timeout(in seconds) - Sets the maximum time (in seconds) to wait for the shutdown to compplete before the service for a particular SID stops. This timeout should be set high enough to give the database time to complete the shutdown. If this is lower than the time needed, you won't have a clean shutdown. You can check this in the alert file.
ORA_SID_SHUTDOWNTYPE = n|i|a - Where n = SHUTDOWN NORMAL; i = SHUTDOWN IMMEDIATE; a = SHUTDOWN ABORT

Failure to do so, then stopping a service in this manner, will do WORSE than a SHUTDOWN ABORT because Windows will just "clean" the memory. This action is akin to performing KILL -F in Windows or a KILL -9 in Unix. Any cold backups are there likely to be useless.

If you want the oracle instance startup automatically when the system reboot, the following key needs to be set.
ORA_SID_AUTOSTART = TRUE|FALSE

Notice that:
1) OracleServiceSID is running does not guarantee that oracle instance is running.
2) Users cannot connect to oracle unless OracleServiceSID is running.