What to do after windows 10 upgrade password wrong?

I upgraded from Windows 8.1 to windows 10 now I had to write in a password but when I entered the password from my laptop there was an incorrect password, what password do you have to enter that from the user that you started with when you created it?

There's a possibility to get into the system anyway, wait a moment, I will look for the suitable video. Otherwise just search on Youtube.

Should be the right video. It's legal as long as you use it on your own stuff.