If you don’t have password You can get it at the bottom of LOGIN page by “Forgot your password/First time login” link
If you have several licenses and can’t understand wich of Hardware id you need to deactivate, you can write to info@paintstormstudio.com and ask to reset your account.
You can deactivate license only once in a week. If you want to paint at several PC every day, you should buy several licenses.