To help us help you, we need to know the model of the computer you are using, and what you are using to connect your computer to the Internet.
Most Dell computers have an Ethernet port that is used for this purpose. It is also possible to use a USB interface between the computer and the modem provided by your Internet Service Provider. An older possibility is to use a dial-up modem to connect over the regular phone line. Which of these do you use?
