There are many Operating System available and it is quite difficult to depict due to its similarity and quite small differences. The easiest way to know what windows operate on your computer is to click on "Start" in the taskbar and select "Run".
Winver is the command that define which windows operate your computer system.
Type Winver in the open window (see below image) and the command will automatically display which windows is actually installed on your computer.
After a few seconds, an image will display what windows is currently installed on your computer, for example, see below :-