Windsor set for EastEnders return
BBC News reports that the "very special episode" will involve her character, Peggy, coming to the aid of son Phil.
In a statement, Windsor said: "It may only be a short visit, but it's a family matter and as Peggy always said 'it's all about family'.
"It is no secret how much I have always loved EastEnders and Peggy Mitchell - and by the number of times I'm constantly stopped by the great British public and asked either 'when are you coming back' or 'please say get out of my pub', it seems they have too."
The soap's executive producer, Lorraine Newman, said: "Peggy's surprise visit is a wonderful treat for our fans, as well as the cast and crew here on EastEnders. It's great to welcome her home."