First, make sure your desktop PC is in good condition. What I mean by good condition is just to make sure the desktop is free of unwanted spyware and other malicious files that could make a desktop computer's wireless connection slow down to a crawl. If you plan on making an older desktop PC wireless then you should really scan your computer for spyware and infections because the last thing you want is something stealing all your system resources when you do not have much to begin with.
What needed to make DESKTOP PC WIRELESS
Let us start by assuming you already have an internet service (not dial-up) and are cruising the Internet with ease. You must have a cable modem connected to your desktop PC. If so, then you're ready to begin your wireless setup. If you do not have an existing Internet service and a cable modem so you'd better stop reading this because a wireless Internet connection on your desktop PC can not be implemented legally without them.
MAKING PC WIRELESS - WIRELESS ROUTER
First, before anything, buy a wireless router. If you have never owned a wireless router 
before then grabbing the most expensive model will probably not benefit you much unless you are planning on receiving a wireless Internet connection from inside of a multi-storey building. In this case a more expensive router will offer some features that are worth the extra money.
Remember when you go and buy a wireless router in hopes of making your desktop computer wireless you'll be glad to know that you will be halfway finished with your mission for wireless internet on your desktop. The only thing left is a wireless PC adapter.
MAKING PC WIRELESS - WIRELESS DESKTOP Adapters
It's actually very easy to add a wireless desktop adapter to your computer's arsenal of computing tools. There are two kinds of wireless network components that you can choose. They are as follows.
1. Wireless USB adapter
2. Wireless PCI Adapter
* Both wireless devices are packed with an installation CD-ROM which quickly installs everything needed to configure and use your PC's wireless internet connection.
A wireless USB adapter is the simplest way to make a desktop PC wireless. The disadvantages of using a wireless USB adapter are the signal strength is significantly weaker than a wireless PCI card. Most people experience no problems with signal strength, so long as they are within range of your wireless router, which is broadcast by the wireless signal.
Basically, to install a wireless USB adapter plugs into any available USB port. In reality, it only takes a matter of seconds to connect a USB adapter and start using the Internet without using cables.
The second wireless device that can make desktop computers wireless is called a wireless PCI (PCI = white slots in a computer) card adapter. This device provides high performance wireless connectivity to your desktop PC with extended range.
Installation is not as hard as you might have thought. Simply remove the side panel from your desktop PC and insert the wireless PCI card in one of the white slots inside. There is only one way the card can be installed. Reading the directions that are included when you purchase your wireless networking device is by far the best thing you can do to ensure a smooth installation and start up your wireless connection.
