When Windows 7 is not registered in time, the background of the black screen appears with a message that indicates that the copy is not genuine. This article explains how to restore the background of the screen so that the copy of Windows is validated.
You can restore the image of the screen background by doing the following:
Click Start , type display in the search box, and then click the icon Display.
Note: If an administrator password or a confirmation is requested, type the password or provide confirmation as necessary.
In the navigation pane, click Change color scheme.
In the Color Scheme list, select Windows Classic theme, and then click Apply.
In the Color Scheme list, select Windows 7 Basic, and then click OK.