Hi Subash

Make sure your setting of allow remote desk top is there, nobody change it.
then Try telnet server port 3389 and see if there are any problem happen through the network, if problem happen, try to see is there any logs in Network threat protection, as your comments, if you disable SEP ,then remote desk top works, then check if our Network threat protection got any log about this connection.
if you can not find any logs in NTP log, then try to add an firewall policy to allow TCP 3389.

only my personal suggestion, wish this can help.

Ivan

Hi,

        Please let us know the following :-

• SEPM version installed on this DC
• SEP Version installed on this DC
• Symantec Endpoint features installed on this DC
• Do you have any other Firewall which is enabled

SEP  Clients has 3 componets

Anti Virus and Anti spyware
Network Threrat Protection
Procative Threat Protection

Out of these 3 which are installed on the Domain Controller

Network Threrat Protection is the firewall componet from SEP

If NTP is installled.  We can do 2 things

1. Uninstall NTP from Add remove Program/ Modify    And Cross NTP
2. Modify the   firewall rule to allow "Block Remote Administration"

enabling the rule will allow Remote Desktop connections onto the computer.

when the symantec services is enabled its blocking your RDP.
If you dont have network threat protection installed, you may try this. from Microsoft

How to configure RPC dynamic port allocation to work with firewalls

http://support.microsoft.com/kb/154596

you may try this.

go to start - run - ncpa.cpl
right click on local area connection and click on properties.
if you find anything like teefer2 , just uninstall it ..
try to rdp again, it should be fine.