Problem with activation.

I have my nod32 serial, but i forgot my email which I had registrate long time ago. How can i remember my email or change it to another? ?

 

I don't know how can you remember your email address Use an object that could remind you of it.

As for the change , contact your local ESET Customer care . They'll re-send you your ESET NOD32 license and change the emails address in the ESET system for orders.
http://www.eset.eu/support/form or contact information -> http://www.eset.eu/partners

If you use Windows 2000/XP/Vista/7 , use ESET NOD32 v3 or v4