W32 Time Server error

If I am running DCDiag on one of the root forest domain controllers, then it says that it is not advertising as a time server. Can anyone tell me how to solve this issue? I am using Windows 2003 AD native. Below is the error:

Starting test: Advertising
The DC SERVERNAME is advertising itself as a DC and having a DS.
The DC SERVERNAME is advertising as an LDAP server
The DC SERVERNAME is advertising as having a writeable directory
The DC SERVERNAME is advertising as a Key Distribution Center
Warning: SERVERNAME is not advertising as a time server.
The DS SERVERNAME is advertising as a GC.
......................... SERVERNAME failed test Advertising

Try to follow the below steps to synchronize the internal time server with an external time source and to synchronize the client time with a time server:

1. First of all try to open a command prompt, click Start, click Run, type cmd, and then click OK.
2. After that you need to type the following, where PeerList is a comma-separated list of Domain Name System (DNS) names or Internet protocol (IP) addresses of the desired time sources and then press ENTER:
3. w32tm /config /syncfromflags:manual /manualpeerlist:PeerList
4. Now you have to type w32tm /config /update, and then press ENTER.