Open CMD with a privileged user:
Run this command:
w32tm.exe /config /syncfromflags:manual /manualpeerlist:131.107.13.100,0x8 /reliable:yes /update
Replace the IP address with your NTP server.Then, update with:
w32tm.exe /config /update
To verify it is the right source, run:
w32tm /query /source