Oracle database does not start automatic with windows Services.
When we installed oracle software on the windows and created new database Oracle software automatically create service on windows service.msc list.
You can also create service manually by using oracle command. it is placed at location %ORACLE_HOME%\bin directory.
oradim -new -sid ORCL
you can also delete the service with oradim command.
oradim -delete -sid ORCL
When we start windows service of Oracle database, its not start database automatic. To solve this problem you need to modified one window register entries.
go to run --> type regedit --> window register windows open
Then go to following location in register window
HKEY_LOCAL_MACHINE --> SOFTWARE --> Oracle --> KEY_ORACLE11g_HOME
Then on right window you get the following parameter name
you need to modified ORA_DBNAME_AUTOSTART parameter from false to true for database automatic start when service of oracle database start.