How do you connect a laptop to an existing PC internet connection?

If the laptop has an Ethernet port (like a phone port, just bigger), connect the patch cable from it to the modem or router/switch/hub. If it does not have one, many manufacturers (Linksys, Belkin, D-Link are good) make USB or PC card ethernet adapters. Open internet Explorer (other browsers will have different instructions). Choose Tools from the menu bar. Choose Internet Options. Choose the Connections tab. Click Setup. Make choices depending on your current method of connection (DSL or cable - different information needed for each). Call your ISP's Support line for more information.