I hav nokia 6680.after the instalation its shows your lincene is expired.what can i do for it.plz help me

Hi,
Remove KAV Mobile from your phone, restart your phone, get the latest version from here and install it on your phone, see if this helps.
Also,note that if you were using a trial version whose period has expired you won't be able to update KAV Mobile and trying installing the trial version again won't help and will give notification "license is expired.......", in this case to continue using the application you should buy a license.

Regards-
Ross...