Not one AV program can stop you from installing inadvertantly a piece of malware or trojan or such. While its best to ask "How good does AV work?" in the security forum, I'm beginning to encounter people that have the impression (mostly due to the marketing of AV!) that you install their AV and you don't have to worry. Or be careful.
Sadly, nothing is farther from the truth. The most used email program might be Outlook Express and even today just PREVIEWING email is dangerous and can cause infections even with McAfee, Norton or "Your Choice."
As to removing pests. Sometimes you have to read a page about the pest and follow the removal instructions. Sometimes one AV vendor will incorporate removal into their AV and the other will leave it to an instruction on their web site (which will be far cheaper to develop.)
In closing, Norton 2004 is not doing that great on the reviews. Just read -> http://www.cnet.com/Norton_AntiVirus_2004/4852-3513_7-30521466.html?tag=dir
With (at present) over 7 out of 10 giving it a thumbs down, it's not a sure thing you will not find an issue. Prior years were better. I expect Symantec to fix this in 2005. I do not expect them to admit any flaw in the 2004 product. Its their nature.
Bob
I used AVG free edition for over two years and always kept it updated. No problems. Then a couple of weeks ago my one computer was infected with the Opas Worm (probably through my own carelessness). I tried everything with AVG and could not remove it. So I went to Norton and Norton took care of business. Here's my question: On my one computer AVG scans 27,000 files on a complete scan, Norton scans 38,000. On the other computer AVG scans 47,000 and Norton scans 84,000. Big difference. Isn't it possible that some of those files that AVG is not even scanning could be infected and you'd never know it? Thanks.

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