I installed windows 7 on my windows 8 laptop, when I checked to connect to a wi-fi it wouldn't let me

[BaltHD]

Hello, I have recently comed up to this problem: I installed windows 7 on my windows 8 laptop, when I checked to connect to a wi-fi it wouldn't let me. It didn't even showed the networks. Then I couldn't go back to windows 8. SO I created a windows intallation media. And got to go back to windows 8, then again it wouldn't show my wi-fi. When I go to device manager, I see a driver called network controller. Is that the problem? How could I fix it? I checked the Dell Support Site.

Sorry for my grammar.

I have a Dell Inspiron 15 3515

 

[Xergiiok]

Are you sure it's 3515? I didn't see that model on the dell support site.