You first need to make sure you have MySQL Admin installed as part of the MySQL build.
The below article is taken from the MySQL site:
1.) Log on to your system as Administrator.
2.) Stop the MySQL server if it is running. For a server that is running as a Windows service, go to the Services manager:
Start Menu -> Control Panel -> Administrative Tools -> Services
3.) Find the MySQL service in the list, and stop it. Open a console window to get to the DOS command prompt:
Start Menu -> Run -> cmd
4.) We are assuming that you installed MySQL to `C:\mysql’. If you
installed MySQL to another location, adjust the following commands
accordingly. At the DOS command prompt, execute this command:
installed MySQL to another location, adjust the following commands
accordingly. At the DOS command prompt, execute this command:
C:\mysql\bin\mysqld-nt —skip-grant-tables
This starts the server in a special mode that does not check the grant tables to control access.
5.) Keeping the first console window open, open a second
console window and execute the following commands (type each on a
single line):
C:\mysql\bin\mysqladmin -u root flush-privileges password “newpwd”
C:\mysql\bin\mysqladmin -u root -p shutdown
6.) Replace “newpwd” with the actual root password that you want
to use. The second command will prompt you to enter the new password
for access. Enter the password that you assigned in the first command.
to use. The second command will prompt you to enter the new password
for access. Enter the password that you assigned in the first command.
7.) Stop the MySQL server, then restart it in normal mode again.
If you run the server as a service, start it from the Windows Services
window. If you start the server manually, use whatever command you
normally use.
If you run the server as a service, start it from the Windows Services
window. If you start the server manually, use whatever command you
normally use.
8.) You should now be able to connect using the new password.
These details are also found at the following link: