How to check Windows version, edition and Service Pack information
The quickest way to find out details about installed Windows is to use keyboard shortcut WINDOWS KEY+PAUSE. The latter key might be named PAUSE/BREAK on some keyboards.
Other method is to right-click (My) Computer or This PC in Start menu/screen or Desktop and select Properties from the menu.
Windows XP Start Menu, My Computer right-click menu. Click Properties to see general system information.
In Windows XP, see what's written in the System section.
In Windows Vista, 7, 8, 8.1 and 10, see what's written in the Windows edition section.
To check whether your OS is 32-bit (x86) or 64-bit (x64), see the System type line in Windows Vista and later. In Windows XP, if there's no mention of "x64" in System section, then the OS is 32-bit edition.