ORA - 12560 - TNS protocol adapter error

c:\Windows\System32>sqlplus sys as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Wed Mar 26 16:25:03 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Enter password:
ERROR:
ORA-12560: TNS:protocol adapter error


Enter user-name:

How to resolve this ?


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search for the service and start it
Run-> services.msc - search for WAREHOUS -> Start the service.

This did not help either !
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One of the web sites said a ) set the oracle_sid and b) net start.

1.
I had to stop it first and restarted it - no luck !



c:\app\Administrator\product\12.1.0\client_1>set oracle_sid=WAREHOUS

c:\app\Administrator\product\12.1.0\client_1>net start oracleserviceWAREHOUS
The requested service has already been started.

More help is available by typing NET HELPMSG 2182.


c:\app\Administrator\product\12.1.0\client_1>net stop oracleserviceWAREHOUS
The OracleServiceWAREHOUS service is stopping...........
The OracleServiceWAREHOUS service was stopped successfully.


c:\app\Administrator\product\12.1.0\client_1>sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Wed Mar 26 16:51:21 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

ERROR:
ORA-12560: TNS:protocol adapter error