Have you re-registered, as after 14 months (your just over a year) you need to register for iAVS updates. They will then send you a new registration key.
Although, I would have thought you should still be able to see the a icon. So I would suggest that you try a repair of avast. Add Remove programs, avast! Anti-Virus, Change/Remove button and scroll down to Repair, click next and follow. You need to be on line to do this.