Setting your own time server (or perhaps pool.ntp.org) in Windows

http://www.timetoolsglobal.com/2013/06/21/how-to-synchronize-microsoft-windows-to-a-ntp-server-1/

Single Command for Windows servers, to use NTP

w32tm /config /syncfromflags:manual 
/manualpeerlist:0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org

After that, the trick is to tell the windows server that the time configuration has changed, this is done with

w32tm /config /update

Finally, tell the time service to update

w32tm /resync

The following command will tell you where the server is getting it's time from 

w32tm /query /source