Hi Manish,
You can open the command prompt (CMD.EXE) logged as <sid>adm and perform the commands.
Test the passwords for your CONTROL and SUPERDBA user.
You can also check the services in the Windows Services to ensure that they're up and running:
If it's a local database you can also try the following command:
#dbmcli -d <dbname> -u control,<password> db_state
#dbmcli -d <dbname> -u superdba,<password> db_state
#dbmcli -d <dbname> -u superdba,<password> -uSQL superdba,<password> db_state
#dbmcli -d <dbname> -U c db_state
Regards,
Luis Darui