Please help Avast 4.8

[ebruuras]

Hello moderator.
Just a while ago on internet by cerdircard ı purchased avast4.8 pro for 2 years.Somehow computer insistently keeps telling that ı have invalid licence key... I carefully noted down all  numbers and letters double checked it but still ı get that "invalid licence key" notification.

What can ı do.?
,ebru uras

[Lisandro]

See the tutorial:  http://www.avast.com/files/tutorials/insert_key.htm
Please take a look here: http://www.avast.com/eng/faq-invalid-license-number.html

[ajit.s]

avast 4.8 pro is best...........javascript:void(0);