If you right-click the start menu in XP and click Explore, you get essentially the same Explorer window as Windows 7. What I think MS did, just from what I have seen in my own experience, is that people used the "Explore" in XP more than "My Computer," so they made the "Computer" functionality work like the "Explore." Even the most novice users here seem to always use the "Explore" window and not the "My Computer" (they don't even know what it is, even though it is quicker to open than "Explore").