Are you feeling glad? During last few updates, Microsoft has fixed(?) this annoying notification to a greater extend. However if you want to reproduce this error do the following:
Disable your network adaptor.
Connect your computer to another available connection (Preferably to a tethered connection)
Disconnect from the new network
Enable your default connection

Now watch the notification popping up and the network connection with “famous” yellow triangle (Warning) until next restart.

for Windows7bugs
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