I cannot recommend any Symantec (Norton) or Mcafee security products. Ever.
If you just MUST purchase an AV product, I would take a look at Trend -
http://www.trendmicro.com/home/default.asp
I didnt run AV at home for YEARS. Its more about your habits than anything. What I have always had is a firewall... Either software based or hardware.
For others, unless on dialup, I recommend:
1. Hardware firewall (router). Pick your poison, it almost doesnt matter.
2. Any two adware/spyware & prevention/removal programs. Here are three:
--- Ad-AwareSE
http://www.lavasoft.de/
--- Spybot 1.4
http://www.safer-networking.org/en/index.html
--- Windows Defender (2000/XP only)
http://www.microsoft.com/athome/security/spyware/software/default.mspx
3. Antivirus - it seems certain combos dont play nice together. While Ive never had trouble with say AVG, you might. It may help (with any software) to read the forums for that product to see what others say. Most programs have either a dedicated forum or you can find an unrelated forum out there discussing that product. Make sure for AV or any other program, that your operating system is supported.
--- AVG an excellent free antivirus program. Small footprint (doesnt "own" your system like Norton).
http://www.grisoft.com/doc/1
--- ClamWin is another popular AV program.
http://www.clamwin.com
--- Avast is yet ANOTHER AV program. Like the others, its free.
http://www.avast.com/
--- AntiVir, works, still free.
http://www.free-av.com
4. Browsers... I use IE all the time but if you spend time in the bowels of the internet, or seem to always be having trouble, make Firefox your default browser.
http://www.mozilla.com/firefox/ There ARE other choices even but I like IE and Firefox if neither of those will work for you, then likely none will.
5. Email... Nothing wrong with Outlook Express but it, like IE, is always a target for evil. You might try Thunderbird instead if express gives you fits.
http://www.mozilla.com/thunderbird/
Backup your data. I dont mean the whole machine... while thats a good idea too you may not have the means or the space. I mean just data... the kind you normally forget... this is a quick, FREE, easy way:
http://fabs.dyndns.org/autobackup/index-en.htm