My computer is running windows 8.1, but I don't know most other details since it was custom built by someone else.
When I plug my ethernet cable into another computer, it works normally, but when I plug it into the computer having problems, it is detected but there is no internet connection.
It worked before, and I don't know what caused the problems.
For a few weeks now when the ethernet cable is not plugged in, there is a red cross on the internet connection icon on the bottom right of the screen as normal, but when it is plugged in, rather than connecting to internet the red cross is replaced by a yellow exclamation point.
So far I've tried most of the things technologically people like me are capable of multiple times, including unplugging and replugging the ethernet cable, restarting the computer and resetting the livebox.