stillirise,

There may be a way to breach the security of this software but I am unaware of how. You can either convince your son to remember the password or you will need to format and reinstall to be able to use the system. All of your data will be lost and you will need to reinstall any programs currently installed on the system.

Hopefully your login name is not already Administrator.  If no, use Administrator for the login name & no password.  You should be able to get in that way.