What version of Windows am I running?

The easiest way to determine which version of Windows you are running is to locate the My Computer icon on your desktop. Give it a right-click, and choose Properties from the context menu that opens, to access your system properties.

The System Properties will open. Depending on the version of Windows you have, there will be more or less tabs than shown on this screenshot.

However, regardless of the version of Windows you are running, the selected tab should by default be the one that lists your system's properties and technical support information, including at the top the main Windows version running on your computer.

In this screenshot, the Windows version spreads across two lines; it is Windows XP Professional. "Professional" indicates which "edition" of Windows XP is running. Further below, "Service Pack 2" indicates that the Service Pack 2 ("SP2") has been installed.