If you’re running Windows VMs beneath a Linux KVM host, you’ve very likely been plagued by an annoying issue: they start up with the wrong time by several hours, every time they’re rebooted, no matter what you do.
The issue is that Windows syncs its time with the local hardware clock, and in KVM’s case, it generally provides VMs with a “hardware” clock set to UTC regardless of what the real hardware clock’s time zone is set to.
Here’s the fix: on your Windows VM, create a new text file called UTCtime.reg, and populate it with the following:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
"RealTimeIsUniversal"=dword:00000001
Now you can just double-click the patch file to import it into the VM’s registry, then reboot the VM. When it comes back up, it’ll come back up with the correct time (assuming your hardware clock is set to the correct time, of course).
IDK about y’all, but this one had been pissing me off for years; it’s nice to finally have a fix for it!