Today I Download Avast 5 Pro. I Thought That My Avast 4.8 Professional Will Work On It. But It Has New Licensing Technology Of Activation Through File. Finally I Found Convert 4.x Key To Avast 5 Key. But It Is Asking Username And Password. Tell From Every I Can Get This Thing.
Hi bangre, welcome to the forum 
The link in Avast! 5 is wrong. This is the correct one :
http://www.avast.com/resend-license.php
You should use the SAME email address as you used when you bought your licence.
Greetz, Red.
Actually, we fixed the link in the program so it’s now correct.
So the button on the Subscription page should now work as well.