Norton Antivirus 2011 - 1 User/3 Pc [Old Version] Norton AntiVirus 2011 offers fast, powerful protection that safeguards against viruses and spyware Stop viruses and other threats before they can do damage Stay safe with up-to-minute protection that wont slow down your PC Detect and eliminate spyware cybercriminals can use to steal your personal information Know when applications are slowing down your PC, so you can make changes to improve performance