OSX does not change the system clock when you adjust the time. Windows changes the system clock. What you need to do is set OSX to tell it that your timezone is GMT and boom your problem is solved because it will read the system clock and believe you are on GMT while windows adjust the system clock OSX takes the system clock and uses software to adjusted the display time.as far as i know (which is limited because i stopped using bootcamp/windows a few months ago) you will need to forgo having the right time in windows. the issue has something to do with windows using hardware to set times and the time zone. meanwhile i think mac os x takes the hardware clock time, and then adjusts it using software according to what time zone you have set. or it could be the exact opposite. anyways, the two systems have different ways of accessing and setting the time.