I have a Windows 7 Ultimate machine where the wireless adapter all of a sudden started having trouble connecting to wireless networks. Whenever I go to a new place and try to connect to a wireless network, it says that the DNS server is not responding, and tells me to go unplug the router and try again. After several locations in a row telling me this, I began to realize something was wrong with my adapter, not the routers.
I am no longer asked to identify the security level for any new networks (Work, Home, or Public) like I used to be (it defaults to Public now - with the park bench icon). Often, resetting the router doesn't even work. Running the Windows 7 troubleshooter doesn't give me anything better than the advice to reset the router. However, the adapter will still connect to the wireless network at my main office without any problems.
Does anyone know why a wireless network adapter can get so finicky so suddenly?