Auditing password security level is important to have an idea if the system is secure or not, sometimes system administrators forget about using the secure password and leave it weak to remember it later, this is not good practice.
To check Mysql password security or recover a lost one you can use MysqlPasswordAuditor, this tool is free and have a simple wizard that will take you to recover your lost password using dictionary based method.
The installation is as any program you start by executing and follow the wizard next you give it server IP , the port used , root user name and password dictionary file. The program can be run on any platform including Windows XP, 2003, Vista, Win7. the most important is list file where you can find them all on Google =).