The Live environment sets and writes the time in UTC to the hardware ("BIOS") clock. Which of course borks it for Windows. (see Ubuntu bug 1703479)
Is there a boot option or similar to make it not do that?
Either:
- set it so use localtime in HW clock, or
- set it to never write to the HW clock (after all a live CD should not make changes to the system, at least not automatically)
- maybe some other solution
PS: The mentioned bug was reported for version 17.04, while it happened to me with 18.04 (ubuntu-18.04-desktop-amd64.iso).