Changing the NTP update interval on Windows 10 / 8 / 7

Open the registry editor and browse to: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\Services \W32Time\TimeProviders\NtpClient

Select - SpecialPollInterval

The default decimal value will be 604800 seconds - 7 days. Change this to whatever value you wish. So for example, setting this to 3600 will force the NTP service to perform an update every hour.