Dell Inspirion 15 N5030 installed windows 7 does not have a network driver help pls

I put Windows 7 on my dell inspirion 15 N5030 laptop. It say there is no network driver installed. How do I determine what device driver I need to install & do I need to install just it or do i need to install all the dell drivers for that laptop. I did not buy it new -i bought it used & do not know what devices it has in it. I can follow directions if given them step by step. I had a dell before this that I had to install all the drivers for using xp and it was a nightmare getting the right driver & installing them properly but I did get it done finally lol. In fact im on a dell laditude right now but it has windows 10 and 10 had all the drivers  needed for this one. i also tried to install 10 on the inspiron but it would not install at all so I put in windows 7 instead. Any help is very much appreciated as the dell i'm using now is old and worn out lol. It was my brothers then my moms & who knows where my brother got it from and i need to get the other one working before this one quits altogether