I’m finding an windows client application, but I can’t find any that’s compiled.
It’s very stupid for me… Windows have no compiler… so I have no way to get EXE file. So this pseudo “clients” are for nothing. Installing Visual Studio or something else is no way (why do it on server?)
… linux client is has self instalation script… I don’t see any Windows client with self installation script 
Note… I find first here … https://github.com/Lone-Coder/letsencrypt-win-simple/releases/tag/v1.9 … why download link is not on home page… missing logic 
I have had great success with using https://github.com/Lone-Coder/letsencrypt-win-simple/ for my Windows server.
The project is active and you can get the compiled builds here: https://github.com/Lone-Coder/letsencrypt-win-simple/releases
What project have you been trying to use that does not include the compiled program?
EDIT: In response to your edit:
GitHub has a structured layout and the releases are on the homepage of the project (see screenshot).
You can try https://github.com/kelunik/acme-client if you have PHP installed. I fixed the key generation on Windows today, tests are working, but I couldn’t try it on a server yet, because I don’t have access to one.
Working with Cygwin on Windows: https://github.com/Neilpang/le
