I’m new to this impressive forum so a big hello from Central Brittany. We’ve been here 4 years & enjoying life greatly! I’m an ex electronics expert & a dab hand with a computer if anyone has any questions!!
We live in a neo-Bretagne style house built mid-70’s. All the wooden windows have small screws in them fitted on the verticals. Inside & out! The screws are perpendicular to the frame & not completely screwed home. Please see the photo!
Can anybody tell me the purpose of these screws please?
I was going to suggest perhaps used to hold the frame for a mosquito net… but they’d only be on either the inside or the outside but not both. So I’m afraid I’ve got no idea But I’m now curious to know too
Many thanks for the responses…I should have said that there are always 3, 4 or 5 screws on each vertical frame member…depending on the window height. Only the vertical parts of the frame. They’re between 30 & 50 cms apart.
Ohhhh I love a mystery . Welcome to SF, sorry no idea, mozze net seems most likely but odd both in and out. Unless they did it one way, realised it didn’t work so had to put them in the other way and never got around to taking off the unused ones??
Have I opened a hornet’s nest? No prizes I’m afraid!
So here’s a photo of the whole of a frame. If you look closely you’ll see the screws on the right hand side of the left panel. The screws are opposite each other…heads facing each other on each panel at the same level.
Looking at the large “bare” pane of glass… I’m wondering if these screws would have held cross-bars to break the look into smaller panes somehow…
I recall one Owner proudly showing me that her criss-cross windows were actually large single panes which could be easily cleaned by removing the “criss-cross”… and this was fixed inside and outside…
just one thought… Your set-up… it looks like it would have been a DIY thingy…
They could have been used at some point to to hold plywood or OSB boards in place, in and out. Possibly to protect the glass whilst work on the house was in progress. Should have been removed and holes filled if that’s the case. That’s all I can think of.
A Welcome from me too Dave, I think the next thing I would be doing was making friends, if not done also, with a few neighbours, and asking them if it is a local thing and thus, do they have them, and thus, why?
I first thought @Stella’s decorative cross sections but noticed the nails are at uneven sectional heights, despite being parallel. So, maybe the Christmas solution instead?
It is very curious and quite an entertaining head scratcher. @David_Spardo has a good suggestion, asking the neighbours.
Meanwhile, welcome to the merry forum, @Dave_C . Please do return to let us know what you discover!
But I’m now curious to know too 
. Welcome to SF, sorry no idea, mozze net seems most likely but odd both in and out. Unless they did it one way, realised it didn’t work so had to put them in the other way and never got around to taking off the unused ones?? 
