I like to do stuffs the command line way, and here a way to configure windows time server on Windows 2008 R2. Open the command prompt, and enter these
C:\> w32tm /config /manualpeerlist:pool.ntp.org,0x8 /syncfromflags:MANUAL
C:\> net stop w32time
C:\> net start w32time
To verify if the configuration which you had just applied is correct, perform a status query
C:\>w32tm /query /statusLeap Indicator: 0(no warning) Stratum: 4 (secondary reference - syncd by (S)NTP) Precision: -6 (15.625ms per tick) Root Delay: 0.0312500s Root Dispersion: 16.0100000s ReferenceId: 0x0A3D0A14 (source IP: 10.61.10.20) Last Successful Sync Time: 2013-02-15 05:40:59 Source: pool.ntp.org,0x8 Poll Interval: 10 (1024s)And voila !