Is gcServer true by default on server editions of Windows?

I have a .Net 4.0 Win Forms app that I run on two boxes, one is a Win7 box, one is a Win Server 2k3 box. The app on the 2k3 box has 2-3 intermittent hangs throughout the day that appear to be large garbage collections, while the win7 box never has these long garbage collections. Is it possible that the default GC on Win2k3 is different than the default on Win7?