The answer is all of the above. Heh.
Here's the short answer. If you are on broadband for gosh sakes go spend the $40 and buy a router if you haven't already. I've seen them as low as $10 after rebates. Netgear or Linksys. Dlink leaves port 135 open, so dollar for dollar, I just tell people not to get Dlink. You end up having to forward port 135 to nowhere, but that's a different dicussion. This step alone will make you immune to worms and external hackers.
Next, install Zone alarm, the personal version is free and it takes a few days to get it trained, but that's not a big deal. It's worth it. I run it.
Next make sure your Anti-virus is up to speed. All the commercial ones are good. Some better than others, but all work well enough.
Finally, you need a resident spy monitor if you use IE. I suggest Webroot's spysweeper. The one coming from Microsoft next month might be good as well. For now, go grab the free trial of spysweeper and let it run resident. You get 30 days and the MS product should be out by then if you don't want to pay for it.
Do all those things and you are pretty durned safe. Just pay attention if zone alarm barks. If you don't recognize what program is asking for external access, do some research before you allow it.
All of those things above won't help you if you're not sure that you're on the proper website. Never follow links in emails if you can help it. Always type it in simply because it could be a redirector that looks like the right thing, but isn't. There's an extension for firefox called spoofstick. It reports at the top of the page what domain you're at. If I'm going somewhere that makes me nervious, I turn it on.
You can also get small versions of Linux that boot from the CD and do transactions that way if you need better security. Macs are also pretty safe, but problems can and do occur. Nothing is secure 100% unless you unplug it from the internet.
You can also get small versions of Linux that boot from the CD and do transactions that way if you need better security.
I've used CD Knoppix to do an XP windows repair. I can really do the transaction on a bootable CD and it will leave no trace on the computer? Mandrake has one also now. Great idea!! I think Next would be to put a legitimate Linux partition my hard drive