I’ve been the proud owner of a Mac Book Air for a little while now. Because of work, I am dual booting it into Windows. A major annoyance, however, has been that everytime I switch to Windows, the Windows system clock has jumped two hours back in time (difference between CEST and UTC).
There reason is that Mac OS X is expecting the real time clock (RTC) to be in UTC, and Windows expects it to be in local time. Luckily, there is a simple fix to this (if you are using Vista SP 2 or Windows 7). Simply set the registry key DWORD value to 1:
This will make Windows use UTC for the real time clock as well!
For more information: