To do this using command prompt. It is good to know that in windows there will be 2 account. One is postgres windows user account. The other is database admin account. Which is also called postgres.
- Edit E:\PostgreSQL\9.1\pg_hba.conf and set the localhost method to trust instead of md5. Do not forget to save.
- Use the usual Windows way to reset the password of windows user account.
- Open up a command prompt and use runas to open another command prompt as postgres user.
- open up Services manager and restart postgresql service. There might be need to update the postgres user account password setting in the service property at this step.
- Now running psql will not ask any password.
- Use the following sql to set the user password
ALTER USER Postgres WITH PASSWORD '<newpassword>'
- Revert the pg_hba.conf localhost method back to md5 .
- Restart postgresql service in Services manager.