They really should have just bit the bullet, changed the names and did something more logical (like \windows\system64 for the 64-bit components). For backwards compatibility, they could simply create hard links just for existing 32-bit applications. There was also significant code changes required for compatibility with UAC when Vista was released, I think that would have been a good time for the transition. Kind of like ripping off the Band-Aid all at once. Yes, there would have been more hand-wringing, wailing and gnashing of teeth ... but that was happening anyway with Vista.