The procedure below only works for Window OS but the same method should work for other operating systems.
Start command-line: keyboard shortcut Windows+r then type cmd OK
runas /user:postgres cmd
You will need to enter postgres user’s password if you are not sure what the password is you should be able to change it through Computer Management under control panel. Please ask if you are not sure.
Once you successfully logged in as postgres user you will need to open Regional and Language settings via the command-line:
Make all the required configurations then restart postgresql service.