Setting up Windows with NTP - Network Time Protocol:
Why would I put a Windows how-to here? So dual/multi booters can use UTC on the other systems that boot off of the same motherboard:
If you are dual/multi booting with Windows you will have to set all systems to use Local Time like Windows. If you don't then each time you boot into Windows it will reset the RTC - Real Time Clock - on your motherboard to Local Time, which doesn't know about daylight saving, or easily handle moving into different time zones, as UTC does (amongst other problems).
This problem has been bugging me since I bought a machine with Win7 installed on it about a year ago. I have tried the registry modifications (multiple times) to get Win7 to use UTC to no avail.
When I took to Manjaro recently I decided to set my NAS box - ReadyNAS Duo v.1. - as a local NTP - Network Time Protocol server, so it would keep my Linux, Mac & PC-BSD machines' time in sync.
(A slight complication here is that I have no need for my Win7 system to access the NAS, so I'll come back to this.)
I stumbled across a wonderful how-to for setting up Windows machines to use NTP, or a local NTP server. It is quick & easy to do & from my experience it just works (unlike the Windows registry modifications to get Win7 to use UTC).
After using the how-to, I can use UTC on all of my systems without having Windows stuff up the time on one of them every time I use it (to play a game :) ).
Unusually, (because I don't want Win7 to access my NAS - local NTP server) I have Win7 autonomously using international time servers, though the rest of my systems sync with my NAS - local NTP server, which uses different international time servers.
The inevitable minor time variations that will exist between the international NTP time servers is acceptable to me, & won't last long after booting into the non-Windows system before being corrected by my local NTP server.
Here is the truly great how-to, enjoy: