The older version of Symantec Antivirus cannot be removed.

I did try to install latest version of Symantec Antivirus, But I could not install the antivirus because in the mid it stops and send me an error message which you can see at below. Does someone know how to resolve this? If than let me know I will be thankful to you.

Problem: Error 1714. The older version of Symantec Antivirus cannot be removed. Contact your technical support group.
