Forgot Email

I have a client that has Bitdefender installed on their systems and they have forgotten the email that they used in order to register, it has since ran out of time and needs to be re-registered but we are unable to see the email associated with it since it blocks out the majority of the panel and says you need to register. We have the license keys that were used but is there anyway that we can find out what email they used to register the accounts?