Backup failed using pg_dump from command promt

I have a DB in a Windows Server 2008 R2 and I want to automate the backup process using a batch file with a script which should run based on a task in the Task Scheduler. The dump command is as follows:

pg_dump -E win1252 -f d:/backups/myBackup.backup -F p -n schemaName -h localhost -U postgres -w dbName

Also, I have included the password information in the pgpass.conf file located at c:\Users\UserName\AppData\Roaming\postgresql folder with the following format:

localhost:5432:dbName:userName:password

If I manually run the batch file that contains the script I get a message saying that "the connection to the database failed: fe_sendauth: no password supplied".

What am I missing?

With respect,

Jorge Maldonado