Always start Oracle DB in Idle State
Starting and Stopping the Database with Oracle Administration Assistant for Windows


  To start or stop the database:
  
  From the Start menu, select All Programs, then Oracle - HOME_NAME,
  then Configuration and Migration Tools, and then Administrative
  Assistant for Windows.
  
  In the console window, expand the Oracle Administration Assistant for
  Windows tree structure.
  
  Under Databases, right-click the name of the database, and from the
  menu, select from the following options:
  
  Connect Database
  
  Start Service
  
  Disconnect Database
  
  Stop Service
  
  Startup/Shutdown Options
  
  Process Information


At Startup/Shutdown Options, you can set whether the instance should start when the Windows service belonging to that database instance starts.



Another method is to use the command line, disabling the automatic startup of the instance of database ORCL:

oradim -edit -sid ORCL -STARTMODE manual