I've had first hand experience with Norton Anti-virus's infestation and subsequent removal. IMO, it's horrid. Not only is it bad at finding or cleaning any viruses, removing the actual program itself is like trying to exorcise some sort of PC demon-spawn. It embeds itself and simply won't let go. Symantec has actually released separate programs intended to remove the program (which also don't always work), because people complained about the uninstall not working (sorry, I don't have the link ATM to confirm this, but I have seen it myself).
The President of Solid Oak software, Brian Milburn, in a statement:
In my opinion, Norton products are worse than any virus I can think of
That pretty much sums it up. (Source: PC Magazine
Now that my rant is over (sorry), I'd recommend either NOD32
(which has been highly recommend to me and others here on the forum quite a few times) or AVG Anti-Virus
(which is free.) I've used AVG on quite a few computers and I personally like it quite a bit.