Changing the Email Address on my License

Hello, can anyone help me to change my email address for my license? I purchased Avast Pro when I was using a different ISP provider. I need to change that email address but I cannot figure out exactly where and how I can do this. I thought that I had done it but I find no record of it. I cannot create a new account because (1) I purchased the product with a different email address; and (2) it requires that I provide a password for the old account–and I never did create an account. I am stuck. I hope tht someone can help. I will also send another ticket hoping that someone will answer soon. Thanks for helping.

I purchased Avast Pro when I was using a different ISP provider.
get a ISP free mail ..... like Gmail / Yahoo / Hotmail then you want have that problem again ;)

contact avast sales http://www.avast.com/contacts

Thank you for the information. I am so upset with my Avast Pro 7 that I am no thinking clearly. You do have a sense of humour! Thanks but no thanks, I still to my MS Outlook mail client. I use the free ones for other things. Thank you.