I happen to use the NTP servers in the US for synching all of my servers. So - how to set these? A few simple commands - stop the time service, set the sync option with server list, set as reliable and start it back up - the last two commands show you the configuration and status.
Open a command prompt (cmd) using Run as administrator and enter the following (careful, second line is wrapped):
net stop w32time
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"
w32tm /config /reliable:yes
net start w32time
w32tm /query /configuration
w32tm /query /status