Last night I read a short story "The Gothic Window" (1944) by Dorothy Quick. When one comes to think about it, this element of an "evil" window seems to be very popular. Besides the story by Quick, "The Music of Erich Zahn" by H.P., "Different Skies" (1999) by China Miélville or "Closed Window" (1903) by A.C.Benson come to mind. Does anybody know more stories dealing with this theme in fiction?

The Haunted Woman by David Lindsay.

"The Gable Window", by August Derleth.

"He", by H.P. Lovecraft.

Not an evil window, but a weird one: "The Wonderful Window," by Lord Dunsany.

There's an uncanny window in John Bellairs's The House with a Clock in Its Walls. (NB From the trailer I've seen, the movie must have almost nothing of the charm of the book.) There's also one such in Derleth's The Lurker at the Threshold, as I recall. Lars Walker has windows into other worlds in Death's Doors and, I think, Blood and Judgment -- in a sort of between-place.