How to know if a Network Adapter is installed in my computer?
You may determine whether a computer already possesses a network adapter looking 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.
In notebook computers, look for a thin, removable metal device roughly the size of credit card, but thicker.
In any type of computing device, look for a small external device connected to a USB port. For computers running Windows, open the Windows Device Manager. Device Manager can be accessed from the Hardware tab of the System Properties section of Windows Control Panel.
Can you see “Network Adapters” on the “Device Manager” list?
YES: Click on the sign to the left of “Network Adapters”. This will display a list of all the network cards on your system, including Ethernet, wireless, infrared, etc
NO: The network card is either not correctly installed or there is no network card present in the machine.