Please help me get my window open

[ShouldI101]

We want to put Christmas lights outside but we can't find the key to open the windows. I've been watching all sorts of YouTube videos to try and pick it but getting nowhere.
Has anyone done this?
What happens if unscrew the screw thing beside the lock? Does the whole window fall out?
FFS, it's the smallest flimsiest key I've ever seen, how can it be this hard?

Ask on here
www.reddit.com/r/Locksmith/

You'll need to join Reddit but it's not hard and they don't send a lot of spam or anything. Very useful site.

Is there a number anywhere on the lock? If so, it is likely to be the type/style number for the key. A DIY store or somewhere like Screwfix should sell replacement keys.

There is not a single identifying feature on the windows or the locks. They are really old windows.

I was hoping to just put the cable for the lights through the window but I think we will need to buy some kind of outdoor cable extension thing and just have permanently closed windows.

we had this when we moved into this house and the only solution was to buy new handles as even the two million keys the glass guy brought with him not one fitted so we went for push button ones no key cost about £29 each from local DIY store

£29 each is a bit pricey - try Ebay - we got some for less that £10

try to unscrew the two screws, the second one might be hidden by the handle.
once unscrewed, pull it out, open it with a standard door handle or spoon :)
access done.
second stage, try to reach the mechanism of the lock from behind, unlock it or change it to push button.

Buy battery outdoor lights?