It has been a challenge to support users on the change from Win XP to 7 but nothing too out there since it still was fairly close to the windows look and feel. I've been running Windows 8 on my office laptop for about a month now, and the changes are so significant to the daily use of the windows interface that the user support is going to be very difficult. I still am struggling with how to find some of the locations where they hid stuff and I'm the tech. Personally, I'm OK with Windows 8 after a month of messing around and have found the way to beat the metro start screen is dual monitors, but rank and file users will really struggle with this change. I think that MS thought users have gotten more sophisticated with the proliferation of smart phones, but honestly, 80% of my users with smart phones really can't even operate their phones with any degree of expertise.