Since you have been able to surf the web with the same computer before, it may be similar to a problem I encountered with my computer. It may have been due to malware/viruses.
Try doing an "ipconfig /all". If you have an IP.
Then ping any url (e.g. google.com). If you get a response, your gateway and DNS are working, which means we have a similar problem See this post:
http://omokute.blogspot.com/2009/12/...ocal-only.html
Try creating a new user, and connecting to the network with that user. It worked for me. I haven't solved the problem yet, but I got it to work again.
Post Originated from Vista Support Forums