On my Windows 7 machine, the default is for
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal to not exist. So, here are Windows instructions:
Hold down the Windows logo key and press R. There, type
regedit. Click OK and if you're using Vista or newer, acknowledge the UAC warning.
Now, in the left pane, there is a tree view. Under
Computer, there will be some things called
HKEY_SOMETHING_OR_OTHER. You should click the + next to
HKEY_LOCAL_MACHINE. Then, you should click the + next to
SYSTEM to get ino
HKEY_LOCAL_MACHINE\SYSTEM. Now, expand
CurrentControlSet, then inside it,
Control, and then
TimeZoneInformation. Now, right-click the entry for
RealTimeIsUniversal and select the option to delete it. Alternatively, you could set it's value to 0.