I just had it happen
, trying to run it using the Start/Run sequence.
My cure is to not try to run it using the RUN command. Start/Run...type cmd, the enter the netstat command after the command prompt screen appears.
If you already opened the command prompt screen...I would guess that your system partition may need to have chkdsk /r run, then defragged. My experience is that Windows acts funny when files are tremendously out of order.