Reactivation With New Motherboard

I've recently set up my WHS on an older emachines box with a Pentium 4 CPU. It works, but its not exactly new. I don't need anything crazy, its only for filesharing. My only concern is if the motherboard fails since the system is already pretty old.

Is microsoft okay with re-activations on new motherboards if you call and explain, like they have been with the regular windows OS? Or are they more hard-line with the server OSes and force you to buy a new copy if the hardware fails?