A PC on the Internet, another no longer works?

It has recently been the case that when my PC is on the Internet, the Internet no longer works on my mother's laptop. We use these links for LAN for the socket and if you connect your PC to the same link at the same time as mine, it works again. What could you do?

It is possible that these devices will not work properly if the wiring in the house is not clean. This is especially a problem in old buildings. A laptop usually has Wi-Fi. It's easier than via LAN. If the reception in the house is poor or the router is too far away (or in a different room / floor), a Wi-Fi repeater can help.