MS holds the lions share of the market, and it doesn't control the hardware. You factor in those commercial realities and you then should understand how that is different to a few amature OSs such as linux etc, where they can ensure the drivers are readily available. The point of this thread is that with XP or later, MS has dropped PAE, because it cannot ensure that PAE aware drivers will be avaialble, this is a commercial decision yes, but it is reality none-the less. You need a 64bit OS to address more than 4gb of ram under Windows period. that is the point of this thread, and as i said, if you want to discuss the merits of this further i suggest you start your own thread.