Due to changes on Facebook side, Angry Birds Friends is no longer able to support Facebook login and progress saving on Microsoft Windows version of the game.

To keep your account progress safe and stored, and avoid potential account loss, we strongly recommend Microsoft Windows players to sign up to Red's Club and create your own Red's Club account.

For more information on how to sign up and connect your game with Red's Club, please refer to this article. 

https://roviosupport.helpshift.com/hc/faq/2264-how-do-i-save-my-in-game-progress-with-red-s-club/