I, too, am having the clock issue on my seven-day-old Surface Pro 3. The SP3 came with Windows 8.1, and I upgraded to Windows 10 right away. Windows 10 drivers were obtained from the Microsoft website and installed according to the instructions given. All
applicable Windows updates have been applied, including a firmware update. I’ve done the hold vol-up and power button thing, reset Windows, and clean installed Windows.
When I shutdown the PC or it goes to sleep, the clock stops. Thus, when turned on or woken up, the clock (date and time) is set to whatever it was at the time of shutdown/sleep. The behaviour is the same regardless of whether or not the PC is plugged in.
I’ve seen several software solutions on this thread for, what appears to be, a hardware problem. Sure, I can schedule a task and have w32tm.exe resync the clock every time I log in. However, that does not work if there is no internet connection. Secondly,
it’s a work-around for a hardware issue.
I can’t believe that, here I am in 2015, with a new PC (and not a cheap one) that can’t keep time. I have read this entire thread hoping to see an upcoming Firmware solution or something. But, it seems Microsoft isn’t even looking at this thread any longer.
I bought the SP3 at Best Buy in Canada and it appears I can return it for a refund within 14 days. So, while I like the PC, I can’t tolerate a device that can’t keep time, and I shall return it.