My web browser and apt-get were working until several hours ago, but suddenly, they started to fail. When I do sudo apt-get update, it returns a bunch of failed to fetch messages. I looked for answers on the web, and many of them suggest something went wrong with apt-get. But I don't think the problem is only with apt-get, because I also lost connection to the internet from a web browser. The problem is not with the LAN cable or anything physical because, when I boot on the exact same computer with another copy of the OS (using a bootable USB), I can connect to the internet, which I am doing now. Do you have any idea what happend, and how it can be fixed?
I use Ubuntu 11.04, Firefox 4.
