FSX on dual boot XP/Vista ?

Sorry if this has been asked before, but can FSX be installed on both XP and Vista on a single computer?I currently run dual boot XP 32 and Vista 64, FSX SP1 is on XP32 and runs just fine, however ... with Acceleration on the horizon I'd like to try FSX in Vista 64 to see any benefits of DX10 once its out (yes I have an 8800 card) but as an insurance would like to keep my fine tuned XP32 FSX alive, not to mention my log book ETC.Does anyone see any problems here? I've only ever activated FSX once at a time, but the activation is the worry I have, not sure how many activations I'm allowed at once? I recently bought Bioshock (it can do DX9 and DX10) it allowed 2 activations for the very reasons I described, but after a big outcry, this was upped to 5 activations, not sure what MS's stance is though? hope I can do dual boot FSX on XP and Vista on same machine?Anyone?