Laptop Only Connects to Ethernet, no Wifi

I have a dell inspiron 15 which I had to recently reinstall windows on so everything was wiped out. I reinstalled all the drivers but it wouldn't let me enable bluetooth with wireless switch. Now when I go into Control Panel> Network and Internet > Network Connections, bluetooth appears next to Ethernet but it doesn't connect to wifi and has an 'X' next to it. What do I do?