Windows Vista: Go to your Start/Vista icon, right click over the top of Computer, select Properties, then on the left side of your window pane will be Device Manager. You should see a list of devices on you system. Find the item on the list that says Network Adapters and click the + (plus sign) next to it. If it has a – (minus sign) instead, ignore this step. Under Network Adapters, you should see a list of all network adapters installed on your computer. If you have an Ethernet card, it will be listed here.

Windows XP: Click Start, then right click on My Computer and left click on Properties. Click on the Hardware tab (at the top). Click the Device Manager button. You should see a list of devices on you system. Find the item on the list that says Network Adapters and click the + (plus sign) next to it. If it has a – (minus sign) instead, ignore this step. Under Network Adapters, you should see a list of all network adapters installed on your computer. If you have an Ethernet card, it will be listed here.

Windows 7: Click on the Start button and then choose Control Panel. Click on the System and Security link. Note: If you’re viewing the Large icons or Small icons view of Control Panel, you won’t see this link. Simply click on Device Manager and then proceed. In the System and Security window, click on the Device Manager link located under the System heading. You should see a list of devices on you system. Find the item on the list that says Network Adapters and click the + (plus sign) next to it. If it has a – (minus sign) instead, ignore this step. Under Network Adapters, you should see a list of all network adapters installed on your computer. If you have an Ethernet card, it will be listed here.

Macintosh: Look on the back of your computer for a plug-in that resembles a telephone jack. If the jack is the same size as a telephone jack then that’s your modem. If you see a similar, but wider jack, that may be an Ethernet card.