No error messages is one of the problems. All looks well. I have a good strength wireless connection, I can connect to another computer over the wireless connection I just get page not found errors when I go to internet explorer.
Can you please confirm that the PC can still communicate with the Internet. Its a long shot but... The only other thing I can think is that you may have set up the Internet to 'Always dial my default connection' or 'Dial whenever a network connection is not present' rather than to 'Never dial a connection'.