Does your computer support wireless when you buy it or do you have to separately install a wireless card onto your motherboard?

New desktops Maybe laptops yes.

If not u have to install it yourself

with most pc's you have to buy a wireless router that hooks up to your modem. but some laptops have them built in.... im not too sure though

If you have a desktop PC, I doubt its wi-fi ready. New laptops usually are though, as are some handheld devices.

Whenever you buy your wireless router you will be able to buy receievers that will go in the back of your computer on your NIC Card.

If you need any help setting up a WAN, I would be glad to help.