No connection to internet

[Thundersax]

Hello,
I would like to help my friend set up the internet on his oldie WIN 7, the computer can connect to WiFi, but shows, that it is not connected to Internet. All other computers and smartphones are running properly, so the problem should not be with the router or cable connection. There is nothing wrong with networking. But how can I find out what the fault is and eliminate it. The automatic troubleshooter tells me to connect to Network admin. I hope to find it with you.
I have already released the IPCONFIG command and restarted with new and deleted DNS and rebooted already.

 

[Firewatcher]

Have you tried restarting the router and using the admin password to allow access instead of the WPS button. Pete

 

[Thundersax]

Thank you Pete, very much for your reply. I have not used the WPS-Button.
I have another PC in this room und two Smartphones - All these are working properly..