What window part do I need for this window?

Question

A lot of windows on my sun porch are missing parts of the latch. I am guessing that time and cold has led to the plastic latch mechanism breaking. Some of the windows are missing both latches resulting in the top window sliding down over time and leaving a gap at the top of the top window (think: flies, wasps, and the like).

What is the component called that I need to replace in these windows, and where would I find it? Note: No idea of window make/model. See pictures below.

Here is a picture of a window with the proper latch and "hook"

Here is a window where the part that is hooked into is missing

Here is the latch detail.

Answer 1

It's a window latch and keeper. Unscrew a good one, head over the your local hardware store, and see if they have a match in stock. Pay close attention to the distance between the screw holes and the how tight the two parts are pulled together. They come in a lot of styles, e.g. this would work if the keeper was on a horizontal instead of on a vertical surface:

You can also look online, and worst case scenario, you'll have to go to the window manufacturer to get the replacement parts.