The username for the store admin area will ALWAYS be "admin". Make sure you're typing "admin" in all lowercase as your username. For your password, keep in mind that it is case sensitive and is limited to 12 characters. If you changed your store admin password with the password change tool and used a password with more than 12 characters, the system only recognized the first 12. Type the first 12 characters in only. This is now your store admin password.
If you forgot your password and you haven't received a password reset email from the store admin, or you can't get the store admin password reset tool to recognize your email address, please open a support ticket and we will reset your password for you.