Newer computers often include a network adapter when sold. Determine whether a computer already possesses a network adapter as follows:
In both desktop and laptop computers, look for an RJ-45 jack on the back of the computer. The RJ-45 jack appears similar to a phone line jack but is slightly larger.
For notebook computers running Windows that may contain integrated adapter chips, open the Windows Device Manager. Access Device Manager from the Hardware tab of the System Properties section of Windows Control Panel.