I used to Norton, but then i found AVG
I recommend it becaue its free and it updates everyday. However, you have to tweak to work effectively. you have to set it to use heustic anaylsis and you have configure the email scanner to scan attachments. Other than that its great and one more its free......
if you could get me the exact error you are receiving while try to update, i may be able to help you. I am working as technical support for symantec but knows only little so i joined this form to learn more.
Previously i were useing norton, but when i tryed antivir then it found
many worm viruses that norton had not detected.
And i havent got more viruses since.