No more Wi-Fi after using Fritz Repeater 3000?

I tried to install a Fritz Repeater 3000 on my laptop, which didn't work. Then I disconnected the part and sent it back. Since then, the laptop has no more Wi-Fi. The internet works with a cable.

The repeater determined something during installation. AVM couldn't help me either. Does somebody has any idea? It's definitely just a small thing, but I'm haphazard

You would have to find out exactly how you proceeded, which steps you took and how.
Because a repeater does not necessarily have to be entered "in the laptop" because it only amplifies the signal.