Hope it's alright that I chime in here.
I had this issue once and I tried every single suggested solution online (including all of the above). Nothing worked. The only way I got windows to update and apply the latest patch was by reinstalling the entire OS.
In any case - @Alexadamu9112 try the above suggestions, but if nothing helps, I would suggest you reinstall your Windows. It's always nice to get a "fresh start" anyway