I'm sorry but we'll need a lot more information before we can help you out as we can't see your machine so don't know what you have or how you connect, do you have a router or just a modem.
Post back telling us what OS you use who your ISP is how you are trying to connect, is it via wireless or Ethernet. What anti-virus and firewall do you use and if you have a router what is the make and model.