You have most likely downloaded trial version by mistake.
AVG really is free and should not display such warnings.
Please reinstall accordingly:
i downloaded AVG free 9.0 and now i am being warned that my protection will expire in a number of days. is this correct? is AVG free edition no longer free? must i upgrade in order to continue using this product? i would appreciate anyone's response.
note: i am using windows xp professional sp3.