Dial up modems have 2 phone line connections side by side in the back of a desktop, one is for the wall, other is for your telephone. Laptops have just one phone line connector. Look closely at the little symbols by the connection holes. If you don't have one, Modems (internal or externally mounted), are on eBay, buy a 56K with drivers on disk for your operating system. A few modems can be installed using Windows default drivers (drivers are software operating programs that tell your computer how to regulate and operate a device).