Since you are using a DSL connection, how do you connect do the DSL router, do you use a wired or wireless connection on your computer?

I will assume that you are using an ethernet cable to connect to your router. I have only seen one case in which an ethernet card was not auto configured in a Linux distribution. Can you please past the output of running "ifconfig" and then "lspci" in your terminal on that computer? If you have no network connectivity then you should be able to past those output files onto an USB drive or CD to be transferred to another computer and then paste them here

did you try to run them with the sudo command, "sudo lscpi" and "sudo ifconfig"?