The Windows Phone SDK provides the Environment.OSVersion property which can be used to detect the version of the Operating System uses in Windows Phone (Windows Phone 8 / Windows Phone 7).
Below is a code snippet that demonstrates how to detect the Windows Phone OS Version using C#.
How to Detect Windows Phone OS version using C#?
var WindowsphoneACVersion = Environment.OSVersion.ToString(); MessageBox.Show(WindowsphoneACVersion);