Run these commands from a command prompt:
Stop the time service
net stop w32time
Set 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 connection as reliable
w32tm /config /reliable:yes
Start the time service back up
net start w32time
Test the configururation
w32tm /query /configuration