Problem in offline backup & restore

Hi

I am trying to implement backup and restore feature.

For backup I am issuing the command from windows cmd prompt:

C:\ [path to pg_dump.exe ]\pg_dump.exe -i -h localhost -p 5432 -U postgres
-F c -b -v -f C:\MyBackups\db_backup.backup mydb

For restore I am issuing the following command:

C:\[path to pg_restore.exe ]\pg_restore.exe -i -h localhost -p 5432 -U
postgres -d mydb -c -v C:\MyBackups\db_backup.backup

The above 2 commands working perfect while database is online (running).

However the problem is they are not working while database is offline
(database shutdown)

It is showing the following error message:

pg_dump: [archiver (db)] connection to database "mydb" failed: could not
connect
to server: Connection refused (0x0000274D/10061)
Is the server running on host "localhost" and accepting
TCP/IP connections on port 5432?
pg_dump: *** aborted because of error

Is it possible to backup & restore the database offline? If so what is the
problem in my command.

Please help me.

Thanks

Sreeman