The server is not updating the Antivirus and antispyware definitions automatically

Hi All,

Need help in troubleshooting AV definition installing issue for one of the server.

Problem Description:

                The server is not updating the Antivirus and antispyware definitions automatically. But the other signatures like NTP and Proactive threat protection updates get automatically. Only the problem with AV definitions not getting updated. I tried manually installing the updates which shows “Automatic intelligent updater failed to update signature updates”.  

                I uninstalled the AV client and reinstalled the package, it got updated automatically for 3 days and now again the same issue. AV definitions are not updating even manually as well.

So kindly provide us the work around for automatic AV definitions updates on the system