There have been many film, stage, and tv adaptations of The Turn of the Screw; a lot more than I expected, actually, and as recently as 2009. I haven’t seen any of them but I’ve compiled a list if you’re interested.
The Innocents (1961), directed by Jack Clayton is the most famous one, and to me it’s the scariest of the these trailers.
The Turn of the Screw (1959),directed by John Frankenheimer looks like a really bad tv movie BUT it stars Ingrid Bergman which makes me want to watch it.
The Nightcomers (1972), directed by Michael Winner is a prequel to the novella and looks really, really ew.
The Turn of The Screw (1992) directed by Rusty Lemorande, is set in the 1960s for some reason, and looks epically bad. Why did you make these choices, Rusty.
In a Dark Place (2006), directed by Donato Rotunno is more of a modern-day retelling where the protagonist is a nanny and everything is terrible.
The Turn of the Screw (2009), adapted by Sandy Welch for the BBC looks promising and stars Michelle Dockery and Dan Stevens, making me think this is some sort of Downton Abbey Gothic AU fanfic.
There’s also a 1999 adaptation with Jodhi May and Colin Firth, but I can’t find a trailer. Here’s the beginning clip, if interested.
Last but not least, here is a video comparing four different versions of Peter Quint at the window. What I think is interesting and really unfortunate about all four is that they’re all really clear and close-up. What I think is scariest about the window scene (and the tower scene, and the stairway scene, for that matter) is that the distance and/or obscurity makes it a lot more intense. You fear what you don’t see more than what you do, and putting the governess eye to eye with a random dude outside a window is scary, yes, but more in a “let me fetch my gun” house invasion way than an unsettling and supernatural terror.