Stop the time service:
net stop w32time
net stop w32time
Add the NTP servers to the manual peer list external servers:
w32tm /config /syncfromflags:manual /manualpeerlist:0.us.pool.ntp.org,1.us.pool.ntp.org,2.us.pool.ntp.org,3.us.pool.ntp.org
Set the source as reliable:
w32tm /config /reliable:yes
Start the time service:
net start w32time