Norton AntiVirus - Virus Definition for Windows 2000/XP/Vista
As new threats emerge, Symantec immediately builds new protection updates and makes them available for download on a subscription basis. If your subscription has expired, click here.
The Norton AntiVirus engine is common to the Norton AntiVirus, Norton Internet Security, and Norton 360 products. You can update these products using definitions shown below as supporting Norton AntiVirus.
http://www.symantec.com/business/security_response/definitions/download/detail.jsp?gid=n95