Oracle on Windows FAQ:
How can I automatically start Oracle on Windows?
Change the Oracle services to startup automatically upon system startup (this is the default after installation). Also ensure that ORA_ORCL_AUTOSTART is set to TRUE in the registry (change ORCL to your SID name).
How does one create a new Oracle service on Windows?
Use the oradim utility. For details, see Creating an Oracle service on Windows.
How does one lookup Oracle errors on Windows?
Oracle on Unix and Linux ships with an oerr utility that can do error code lookups. Oracle doesn't, however, ship an "oerr" utility for the Windows platform. The following perl script can be used to simulate oerr behavior on Windows.
How does one schedule OS jobs on Windows?
Use the "at" command. Enter "at -?" from a cmd window for help. Alternatively, navigate to Start-> Control Panel -> Scheduled Tasks. Starting from Oracle 10g jobs can also be scheduled using the DBMS_SCHEDULER package.