Windows is pretty common for control systems in factories. One factory I worked in used a web application, the one I'm in now uses VB applications. One of the control systems I use is running Windows2K. These computers have Internet access too.

Because they're all consumer level OSes now, unless you can afford an enterprise license. Not every organization can.

It used to be perfectly reasonable to run light industrial and test equipment on Windows.

Why are you perpetuating the myth that there is a difference?