Norton sucks, and so does McAfee.
Avast is the best free antivirus.
BitDefender and ESET Nod32 are the best pay antivirus programs.
BEST SECURITY MEASURES FOR A WINDOWS operating system computer or laptop:
Never use any Internet Security Suite, just install separate, different programs for protection, from the ones listed bellow:
Do not use McAfee or Norton antivirus, they both suck. Also anything made by Microsoft sucks.
The best pay antivirus programs are BitDefender or ESET Nod32.
The best free antivirus programs are Avast and Avira AntiVir.
Install 2 antivirus programs, one to run at all times as live, active protection scanner, and another just for on demand scans when you have doubts about any file.
Also install MalwareBytes, at least the free version.
You will also need a good firewall to protect your system from attacks.
First test your firewall with this little leak test utility:
http://www.grc.com/lt/leaktest.htm
You will see that it will penetrate your Microsoft Windows firewall.
It is common knowledge that the Microsoft Windows firewall sucks. Install Zone Alarm or Comodo Firewall (both are free). Zone Alarm is the best firewall ever.
Rerun the firewall leak test and you will see that it cannot not penetrate Zone Alarm or Comodo, you will get a prompt asking if you allow communication or not, just choose NOT.
Install CCleaner to clean your temporary files, cookies and temporary internet files. It will also allow you to remove programs from your startup list (speeds up your system) and any unused registry keys and other unwanted stuff. Just be carefull how you use it not to cripple your Windows operating system.
http://www.piriform.com/ccleaner/download/standard
For your web browser, use either Firefox Mozilla, Opera or Google Chrome.
http://www.mozilla.org/en-US/firefox/new/
http://www.opera.com/browser/download/
http://www.google.com/chrome
DO NOT USE INTERNET EXPLORER (IE), as it is the worst browser, and it can be easily attacked and infected.
As an added security measure, also install the WOT (Web of Trust) tool to all your browsers. It rates all websites, blocks access and also alerts you when you open an unsafe website, thus preventing most internet attacks or virus infections.
http://www.mywot.com/
Good luck.