Hello and thank you for your answer, After many many updates, I used this screen saver without exactly knowing since when it was there ! But suddendly it didn't work, when I decided to use it again. I found the files I deleted in an old pc with windows xp and I copied it in my new pc with vista, but nothing happened, it still didn't work.
But if you are sure Avast doesn't support it anymore, my subject is closed !