The most popular operating on the line designed by Microsoft. 

Part of the windows environment that allows the user  to type  his/her  password before using a computer

The program that is needed to run application installed in the computer

Part of the Windows environment that is displayed after signing in

The first screen you see when you turn on a computer

The screen that appears when you restart  your computer 

It helps protect the computer from unauthorized use

The software that needed to boot up a computer

A very useful device  that needs a software to run programs  and applications

When you right click this icon, you will see the list  of administrative tools