There is also an alternate method if you cannot reset the password, in the configuration file:
Windows
C:\winnt\qb.conf or C:\windows\qb.conf
Linux/OSX
/etc/qb.conf
Add these lines:
database_user = root
database_password = "yourpassword"
You can use any account you wish. However the user account you choose, must be capable of creating and deleting databases.