Windows 7 - Unidentified network access

I have bought a sony vaio laptop nearly seven months agao. It was ok with broadband network as well as with wireless. Recently I was using mainly with wireless connection. But one day I brought it to my office and was checking with broadband connection, I found the message "unidentified network" problem. I googled the problem and tried to find out the solution but failed. I tried in many ways. I am not expert in understanding this thing. I have also gone through several suggestions already posted but none of them came to help me out. It would be highly appreciated it some one could suggest me any step by step solution as I even do not understand why it started working in such a weird way.

Thank you all in advance for your sincere cooperation.

Sounds like you could have the secondary default gateway problem. The link below can help you fix this problem.
Windows 7 Unidentified Network, Limited Access, No Internet Connection Problem Resolved

Thank you very much. Yes, it was the getway problem.

Glad to see that this problem does actually occur sometimes. Easy enough to fix I'd say. Thanks for reporting back in YasSha.