Can't find wifi setting for internet on precision ts5600 desktop after factory reset

I have a dell precision ts5600 desktop that I factory data reset because I could not get it on the internet, it kept saying ether etc. So I reset it and I thought that would fix the problem but I still don't see a setting to connect to a wifi network. Can someone please help. I have it connected to the router for know but only while my boyfriend is working then when he is home I have to push it out in the living room. It's on a server rack with 3 servers that I don't use. I have a 11yr old son who wants to use this to play games so I really need to get this connected to the wifi without using  ethernet.