When looking at network adapters you are going to see a variety of different kinds that you can get. Internal cards are difficult because you will either have to go through the delicate process of installing them, or have to pay to have it done. The best bet is going to be one that fits into an existing card slot on your laptop. The express card options will be the fastest and most stable, but they also have the largest chance of not being compatible with your specific computer. The fail safe is the USB adapter, which is a little slower but almost always works. It is also physically more durable and will take a little more trauma. If you can fit an adapter card then that should be your top priority. These are the main types, and really the only ones that should be considered when buying an external card.