This is for my own reference more than anything else, and taken from: http://lifehacker.com/5742148/fix-windows-clock-issues-when-dual+booting-with-os-x
To fix the wrong time showing in Windows when dual-booting with Linux:
- Launch regedit.
- Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
- Right click anywhere in the right pane and hit New > DWORD (32-bit) Value. Name it RealTimeIsUniversal, then double click on it and give it a value of 1
- Lastly, reboot into Linux or OS X, then reboot back into Windows.
Works like a charm.