On windows 10 we see it has three different types of backgrounds, the desktop background, the lock screen background and the sign-in screen background. we see in this three types of backgrounds the sign-in screen background cannot be changed unless you use an app. If you leave the background untouched, you will see always the Hero wallpaper that is default in Windows 10. If you would prefer to not have any image appear on the sign-in screen , here’s how you can disable it.
If you want To turn the background on the sign-in screen off, you need to be running the 1511 build of Windows 10 that is released in November 2015 . If you don't know what build you have, here's how in this two photos :
If you’re on 1511 build, open the Settings app and go to the Personalization group. Click the Lock screen tab and scroll down to the ‘Show Windows background picture on the sign-in screen’ option. Turn it off and the sign-in screen will no longer show any image.
After , it will show you solid color filled background. To customize that color, go to the Colors tab in the Personalization group and select a different color. You can select one of the pre-defined colors or you can have Windows select one that matches your desktop wallpaper.
Turning the feature Off/On is easy and you won’t need to back into Windows and sign out for the change to take effect .
