Most likely an issue with your access point? What are you using to connect to the Net? If its a cable modem or Fios, connect directly to it and see if you have Net access? If you do, then its likely your router. Reboot it by powering off/on to see if it resets?
Conversely, If nothing on your modem, then first try rebooting it. Can you connect? If still nothing, bring up Command Prompt, and type ipconfig /all and ENTER. Is your network adapter being assigned a IP address/gateway?