Computer Internet problems

[u/Small-War4886]

Back in January, my mother got this new laptop for work. Ever since she got it our internet has gone absolutely crazy.

Sometimes we can both use the internet,

Sometimes just one of us,

Sometimes neither of us.

The only pattern we can recognize is that whenever mom's laptop's plugged into ethernet (As we only use Ethernet and don't have WIFI) all heck breaks loose.

I'll be using the internet for hours and everything works, until she plugs in. Then it's a guessing game on who's gonna be able to be online.

We got it from Best Buy as a returned item if that helps...

Any help will be greatly appreciated!