pg_ctl.exe error code 1057 on windows 7 -- PostgreSQL create user create password

The Problem is : Postgres is running on Wamp but cannot connect to database because the username is not set, or the rule is not set. So when trying to  run pg_ctl.exe  with -U option to change the username I got this error .

pg_ctl.exe error code 1057 
 
This is a windows error code :

Error code 1057: ERROR_INVALID_SERVICE_ACCOUNT - The account name is invalid or does not exist.

That means the account name or the username that was used with this command is invalid , and that because (in my case) I didn't create user , to do so :

go to the PostgreSQL bin folder and run this command :

createuser  --password postgres

you will be prompted by password enter

password:

Enter the password related to the account with username (postgres).

Now you have created a username `postgres` with  a password , a credentials that you can use to login to PostgreSQL server.