// This example demonstrates the PlatformID enumeration.
using System;

class Sample 
{
    public static void Main() 
    {
    string msg1 = "This is a Windows operating system.";
    string msg2 = "This is a Unix operating system.";
    string msg3 = "ERROR: This platform identifier is invalid.";

// Assume this example is run on a Windows operating system.

    OperatingSystem os = Environment.OSVersion;
    PlatformID     pid = os.Platform;
    switch (pid) 
        {
        case PlatformID.Win32NT:
        case PlatformID.Win32S:
        case PlatformID.Win32Windows:
        case PlatformID.WinCE:
            Console.WriteLine(msg1);
            break;
        case PlatformID.Unix:
            Console.WriteLine(msg2);
            break;
        default:
            Console.WriteLine(msg3);
            break;
        }
    }
}