LAN settings

I am having "proxy server" issues and I am unable to connect to internet at all. My connection is excellent, but the real issue is that I cannot configure my Proxy/LAN settings. The boxes are grey and it won't let me make changes. When I say the "boxes are grey" (for lack of better word) I mean that everything in the LAN settings will not allow me to check any boxes (all boxes are left unchecked). I contacted Microsoft tech support, and he thinks I may have a "registry file" problem. Needless to say, as soon as he tried selling me something, I cut him off.
I have a windows 7...any help is greatly appreciated!