I had to extract some files off an old PC the other day. It ran NT 4.0 on a 166MHz CPU with 64Mb of system RAM. The 'user experience' was not a frustrating one, either. Never mind Vista or XP - you'd be hard-pushed to find a mainstream Linux distro that would run happily on such hardware these days. Is the Operating System (you know, that thing that lets you run applications and talk to the hardware) really doing so much more work just 10 short years down the line ?