I have a Dell Inspiron laptop and did a update from Windows 7 to Windows 10. I do have two user accounts with password. After the upgrade I could log in with my user account, but got a black screen with only the cursor visible. After a couple of reboots I cannot log on anymore. So now I see the logon screen, and my user account but get the message that the password is not correct. Same with the other account: the password is also not correct. Caps lock is not on. Anyone an idea how to solve this?