If you’ve recently upgraded to Windows 10, at the login screen, under the listing of user account usernames, you may see some key symbol icons with the word Password to the right of them as shown below.
Presumably this is for those who would like to use a USB key that contains a password keychain. Like a key to your car, a USB drive that contains a long password key can give you access to a computer that’s configured to work with such devices.
However, if you’ve recently created a new user account, but not yet logged in using that new user account, clicking on one of those key icons will results in an error message stating “HRESULT 0x8007ffff.”
Fixing the Problem
You must use the normal login first by clicking on the username and entering the password. Windows will perform the initial account setup. Then logout, and then you should be able to click on the key symbol icon and use that login method.
What’s a bit confusing about this situation is that there’s no way to tell the different key icons apart. They are each associated with a user account, but you won’t know which one until you click on them.
Below are screen shots of this phenomenon.
Windows 10 Login Screen
The top user account name is obscured for privacy. Click the image for a larger view.
HRESULT 0x8007ffff Error Message
Click the image for a larger view.
Iowa City Technology Services 
I have the key symbol on screen, but that is it, no place to enter password. The dots that go in circles is the only other thing on the screen. How to get the Windows 10 going again?
I’d suggest having someone locally take a look at it. Some problems like this one require a person to actually sit down with the computer to fix it.
I am unable login to Windows 10 with my windows / outlook and Local account.
The login screen displays a strange Key symbol and none of my default password is accepted. I’m even unable to change user and user list on left corner is not displayed. Please help!
You may need to take it back to where you purchased it to get support. You’ll need to have them, or someone actually look at the computer.
Windows 10 gives the option of either using a password as usual for signing in. Or…… you can create a 4 digit pin. This is quicker of course. Both the usual password and the new pin option is available when you click the key
Mostly this is cause by a previous sign-in authentication device that is no longer in the machine or is not in use like a finger print scanner. The solution is in https://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_security/duplicate-icons-in-win-10-logon-screen/7b9e29ff-2d3e-4fa9-8e1f-72e222268706 read TSpencer58 comments.
Tnanks for the suggestion.