My win7-64 ultimate has set the clock ahead 2 hours. It appears to have done it in increments of 1 hour, with the second 1 hour shift made sometime today. The first, correct, shift for Daylight Savings was sunday morning. In the clock settings it says Mountain Time UTC-7, but the official time should be Mountain Time UTC-6.
Update for Windows 7 (KB979306) IS installed.
Microsoft appears to be able to turn even setting the clock into a hairball. I need the clock rock solid since I use the computer to record TV programs.