I bought this about 2 years ago and re installed it. Upon launching the product it asked me for a serial no and email. I can't remember which e mail I used. how do I re activate or re register?
It is always the responsibility of the user to keep a record of his/her registration details!
How many email addresses did or do you have? Have you tried registering with any/all of them?
If you really cannot find your details, can you access your Account here? Presumably not, since it also requires your email address.
In the ned, if you still have no success I think your only option is to email infoservice@magix.net, with as much detailed information as you can supply (e.g., original order number, serial key etc.) and ask for their help.