crazijoe

The way I usually set the DC time source is through the cmd prompt.

C:\>net time /setsntp:time.windows.com

then you have to stop the time service

C:\>net stop w32time

then you have to start it back up

C:\>net start w32time

I have noticed that the time.windows.com site is not always reliable and started to use a different time server.
time.nist.gov