|Hmmm, That "Not working... " message doesn't sound like a normal windows message... |
If your wireless connection is good, then you should see 'Status Connected' when you hover over the network icon in the system tray. Cick on the network icon to bring up the status window. Click on the properties button on the 'General' tab. On the properties screen / General tab, select the Internet Protocol TCP/IP item and click the properties button. You will normally want the 'Obtain an IP Address automatically" and 'Obtain DNS server automatically' buttons checked.
If that doesn't fix the connection, try going to the 'support' tab, and then clicking on the repair button. This may at least tell you whats wrong if it can't actually fix the connection. Another helpful bit of info can be gathered from the ipconfig /renew command line command.