Keeping Your Mac and Windows BootCamp Clocks in Sync
This has annoyed me for some time, however I’ve stumbled upon a simple registry edit fix…
Essentially, the incorrect clock setting happens because OS X use GMT time while Windows tries to synchronize with your local time zone, getting confused when you reboot between the two. Apple's own Boot Camp drivers for Windows are supposed to fix this problem, though some users have noticed that it still happens even with the drivers installed.
· To fix it, boot into Windows, click the Start button and type regedit.exe in the search box
· Hit Enter and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
· Right-click anywhere in the right pane and select New > DWORD (32-bit) Value
· Name it RealTimeIsUniversal , then double-click on it and give it a value of 1
· Lastly, reboot into OS X, adjust to the right time setting, and then reboot back into Windows – your clock setting now actually displays the correct time.