Upgrade 8.1 to 10 - locked out - can't type password

[Marcusucram]

I just installed the free upgrade (Windows 8.1 to Windows 10) on my laptop and can not enter the password.
My existing 8.1 account's password had an ? (german umlaut) character and now after Windows 10 (language english US) is installed I see no chance to type in my password. I'm stuck at the login screen...
I already tried the virtual keyboard and [Alt][0][2][4][6], but it doesn't work.

What the heck!! How can I login?

 

[TechFreak1]

You will need to change the language to German, there should be option on the login screen. I used to use the region trick to enable cortana. I had to change the keyboard language to US English to sign in.

However this only works if you have German or another language added in addition to primary set language.

You might be able to change the password using the advanced tools (cmd) under start up recovery (if I recall correctly).

 

[Marcusucram]

There is no option to change the keyboard language. If you press "Shift+Restart", PC boots in "Troubleshoot"-Mode. There you have to login then. Surprisingly the Keyboard layout is in German and was able to login, i.e. verify that I'm allowed to access cmd shell. After that, the cmd shell is shown (still not in desktop mode). It was not possible to change the account password using "net user Marcus blablabla". The account could not be found...
I'm so upset with this... Now trying reset/reinstall...

 

[TechFreak1]

Ah that sucks, looks like a reinstall is needed. Best plug in your hard drive as a slave or into usb caddy and retrieve your data if you haven't backed everything up.