Ok, if you have lost your password and you are the admin of a forum:
Open phpMyadmin and browse the users table, click the edit link beside your name. find the password field.
Next, go to:
This will allow you to generate a password that will work with phpBB 2 in phpMyAdmin.
Copy the block of text that appears after "AFTER:" Example:
AFTER: "THIS PART"
Paste it into the password field on your account in phpMyAdmin and save it. You should be able to log into the forum with your newly generated password.