Can I inhibit WGA nags (and possible capability removal) for off-net Win 7 systems?

I work in a situation where a network involving Windows 7 is used in an environment that is not connected to their own internal network and not the internet at all. However, after a period of time, Windows complains (WGA) about this and in this situation this is a problem.

Is there any workaround to disable these messages and run Windows 7 without having these nags and possible inhibited capabilities? Afterall these ARE legit copies of Windows 7 and internet access is NOT needed nor wanted.