Internet connection (Mystery)

[Teddy07]

I did build the PC for my sister a few month ago and it works totally fine.

 

The problem is that my sisters PC is connected through an unknown source with the internet.  She just discovered that she still has internet even when we removed the cable connection. I don't get how this is possible? I did not build in a WLAN card. It thought maybe the mainboard does have one included but it doesn't seem this way: https://us.msi.com/Motherboard/Z170-A-PRO.html#hero-overview

 

My father has a new second WLAN router which is intended for the security cameras only. I assume these cameras are connected to the new second WLAN router (https://www.amazon.de/gp/product/B001FWYGJS/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1) and they store the video material on another device. I don't live there anymore so I can't see it for myself.

 

Can I see somewhere in windows 10 with which device my sister is connected? We want my sister to connect with the cable to the internet.

 

I am completely baffled

 

[LienusLateTips]

It's somewhere in Network Settings in Control Panel. "Network Map."

[Teddy07]

4 minutes ago, JDE said:

It's somewhere in Network Settings in Control Panel. "Network Map."

That is so strange.

I found out that only one network is available and it provides internet access. That is the one that she is still connected when remove the cable.