The series, which airs during the festive period, sees various celebrities making short autobiographical films.
Windsor and Smith have now signed up to take part in the show alongside Mount Pleasant star Sally Lindsay.
Comedians Johnny Vegas, Jack Whitehall and Harry Hill will also make films as part of the project.
Sky's head of comedy Lucy Lumsden said: "Little Crackers 2 is set to be one of the highlights this Christmas season. We have some of the best actors and comedians serving up some brilliant comedy shorts - perfect for the cosy winter nights."
The stars will join Alan Davies, Shappi Khorsandi, John Bishop, Jane Horrocks and Sanjeev Bhaskar, who have already signed up to take part.
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