Internet does not work on stand-pc, what to do?

No
3

So we have nen stand-pc and 2 laptops. The modem at the stand-pc is now broken and we have closed the wireless router to the place of the modem (modem was downstairs, wireless router in the 1st floor) and that has surprisingly works. But now the internet is not working on my father's stand-pc anymore (connected with lan-cable…)

go

Probably the LAN cable is defective

No

"Unfortunately not.

go

I'm at a loss