If your modem is directly connected to your computer, and you've entered your username and
password to connect in Windows, you should not worry about this error message. It simply means Windows has assigned the internet address to your broadband connection, but didn't assign an internet address to your networking card. Only the broadband connection needs an internet address for the internet to function.
If your modem is connected to a router, this error message means your router is no longer giving an IP address to your computer(s) and should be rebooted. If you need assistance, contact technical support at 1-877-393-2854.