Why does Windows 10 not take my password?

[Windows Central Question]

I've installed Windows 10 but it will not take my password. I know my password is correct but it keeps showing the message that it's invalid.

 

[Pete]

If you're logging in with a Microsoft Account, then log into http://account.live.com and see if that accepts the same password. If not, resolve whatever problem it responds with (reset password, validation).