cann't able to remove application fully

sir/madam, first of all i uninstall akonaditray using Ubuntu software center but its ikon is still in applications while i click it shows a message Could not launch 'Akonaditray' Failed to execute child process "akonaditray" (No such file or directory).then i open filesystem/usr/share/applications/kde4 then i try to delete it Error while deleting.There was an error deleting akonaditray.desktop.Error removing file: Permission denied How can i fully remove it.also suggest any video and photo taking camera software.i use dell inspiron 1525 laptop.