Who or what changed my password
Well you say that Windows passwords cant be changed unless a human does it. Wrong!
I created an admin password "h3nry" (my name is henry) and gave my daughter a password not with admin rights. For several weeks I used the admin password then one day it told me it was incorrect. No-one and I repeat no-one had access to the password nor could anyone have changed it. But it changed.
The keyboard configuration was not changed. No capital letters were used. The password was in fact used in the password prompt.
Now I will not use a password. My daughter and I have decided that it is a waste of time.