All my home PC's dual booting linux/windows (3 I think) are set to think the hardware clock is UTC. Never had a problem, did that at least 5 years ago.

Now relying on that in a production environment ...

Strange, I've never had trouble with it on win10 + Linux. Maybe there's a (third party) driver that messes with the RTC for some reason that doesn't always activate?

Maybe I shouldn't be too surprised that Microsoft's support is broken.

Agreed. Don't bother trying to make Windows give Linux the time of day (pun totally intended), it never works, that's probably by design. Just give up and make Linux accommodate the Windows style system clock, has almost no issues.

That seems like the kind of thing that shouldn't be broken all the time given how common of an issues this is. Perhaps it's not wise to rely on windows.

And that explains why I've had issues trying to use that reg flag Thanks for the info!