Problem connecting to a network

I bought this new laptop and it worked perfectly I connected to the WiFi and it worked

but when I connected it through LAN to get faster download and downloaded windows 10

after I installed windows 10 still connected to LAN. then I disconnected the cable and tried to connect through WiFi, it give me this message "can't connect to this network". I tried to connect it to different network it worked

what is the solution
 
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