Open the Run Prompt by hitting Windows key+R on your keyboard. Type services.msc and hit Enter to open the Windows Services tab.
Scroll a little to find Windows Time service entry. Double-click on it to open a pop-up. Make sure that the service is Started and that it is set to do so Automatically. In the example above, it is set to Manual and Service status is Stopped. Start it and set it to Auto. Save everything and reboot your computer to check if time not updating or syncing error is fixed or not.