Right-click on the My Computer or Computer icon on your computer desktop.
If you do NOT have a desktop icon, click HERE
Click Start (or the circle with the Windows “flag” logo), then right-click My Computer or Computer.
If you do NOT see a My Computer or Computer option on the desktop or in the Start menu, press the Windows key (the button on your keyboard with the Windows “flag” logo) and the Pause/Break key AT THE SAME TIME.
This will open the System Properties window (it may take a few moments to open).
Skip Step 2 and go to Step 3.
In the System Properties window, on the General tab, look under System for the version.
Example: Microsoft Windows XP, Professional, Version 2002, Service Pack 3.