Setting the Root User Password
One of the most important uses of mysqladmin is to assign a password to the root user. When MySQL is installed, no such value is established. This is certainly a security risk that ought to be remedied before you begin to use the server.
Just to clarify, your databases can have several users, just as your operating system might. But the MySQL users are different from the operating system users, even if they share a common name. Therefore, the MySQL root user is a different entity than the operating system's root user(if one exists), having different powers and even different passwords (preferably but not necessarily).
If you used the MySQL Instance Configuration Wizard on Windows (see Chapter 1), you should hopefully have already assigned a password to the root user. Otherwise, follow these steps.
To assign a password to the root user:
Once you've established the root user's password, it's only slightly more complicated to change it.
To change the root user's password: