no limitations, no downsides, straight intergrated into your windows install Also throw in Ryans update pack, .net 3.0 all in one, then use windows media player 11 slipstreamer http://www.ryanvm.net/forum/viewtopic.php?t=4109 (I personally reccomend the tweaked version) And what you end up with is a very neat fully updated xp disc with minimal effort.