Is norton InternetSecurity 2009 enough?

hi there, Is norton InternetSecurity 2009 enough to keep my computer secure ,or do i need anything else ?,i`ve tried lavasoft adware and avg anti virus also spybot s&d all free versions ,but they rarely seem to find  anything,they are probably just running up my cpu, any advise would be greatly appreciated.

Message Edited by catscurlyear on 02-14-2009 02:32 PM