Can't use internet on my web browser

I've been looking everywhere for a solution, but could not find one. I can't get my web browser to work (no connection), but if I run a program like Steam, I can chat with friends and see who is online. When I Troubleshoot my connection problems I get "Windows can't communicate with the device or resource (primary DNS server)" Also, my web browser (Firefox) works fine in Safe Mode with Networking, but not in normal mode. Then after spending hours trying to fix the problem I decided to format my computer by reinstalling Windows 7 Professional. I still have the same problem. I'm dorming at my university, so I can't unplug the router and plug it back in. My ethernet cable is connected to a port on the wall. How do I fix this?

Sounds like an issue for Tech Support at your college. Best Regards