How to make a new notebook faster and more secure

So you just spent a few hundred bucks on a new laptop. You fire it up for the first time and are greeted by your "ninety day trial" of Norton Antivirus to keep your machine protected right from the start. (Or you didn't get any included trial antivirus software, so you just fork out another $39.00+ for a one-year subscription with updates). Great, virus problem solved! After using your new notebook for a few days, perhaps you notice that it takes more time to boot up then you'd prefer. Or you notice that your new technological wonder randomly "slows down"..