Not able to Join PC in Domain

Before some days i face serious issue with domain member client. I make Windows Server 2008 server as Domain Controller. It was first domain in my environment. I successfully created Domain and also DNS.

I check all things were working fine. No error in DCDIAG command. All test were passes successfully.

DNS resolution was also done properly. After that i try to make my PC member of that domain.

I have windows 7 installed on my PC. But whenever i try to join my PC in DOmain i get error Domain controller not contactable. 

All things were proper but then also not able to join in domain.

After lot of try i saw their is Antivirus on server named Office Trend Micro and ports which is required for client Domain connection were blocked. This was the reason why i was not able to join my PC in Domain.

I just simply right click on Antivirus from Task bar and Unload the same and then i was successful in joining my PC in Domain.

If you sure you Domain and DNS is working fine and then also you are not able to join PC in Domain than first thing you need to check any third party Antivirus Software is their or not.