Eicar is a pseudo-virus you can download from the same Symantec-verified dot com (always have Web Safe on - you're not clever or cool to use browsers and add-ons that bar the green ticks, which are one defense). This tests your AV, and Norton passed, detecting and removing even the 'virus' in a double zip with both protocols (the dot com form is so shoddy, Norton won't allow download).
I'M NOT RECOMMENDING YOU DO THIS NOW. Even though it's a sheep in wolf's clothing (the opposite to a real virus), it does carry a danger that your non-Norton AV with your PC could do something undesirable. If you're Norton only, don't bother - I've tested this with default settings (don't change them - if something's set to 'off' it's because Symantec doesn't want you to have problems with a slowed PC or good files being deleted with bad).
The real point of this post is that a certain other scanner missed the 'virus' entirely on right-click scan. Of course, this is probabaly because the eicar 'virus' isn't listed as a threat on their database and/or that it's so crude (a simple 68-byte file that simply looks malicious) that it's ignored as a 'joke file'. I'm taliking about a major AV here, and this is a fairly well-known test pseudo-virus, but i've missed anything to support my 'probably'. i would have thought any AV would've picked it up just to reassure you as to its worth, but right now I'm not confident about that particular 'backup' AV.