Question: how to set up time domain controller in windows 2012 server r2?
Answer: Right-click Windows icon and open [run] and input "gpedit. msc" like follows. Select [Administrative template] - [System] - [Windows Time Service] [Time Providers] on the left Pane, and Open [Enable Windows NTP Server] on the right Pane. Check a box [Enabled] which is upper-left like follows.