open signal

Hi there, I have been trying to connect to a wi-fi signal in the caravan park where I spend most weekends, there 2 signals, the protected one is to weak and the second one is strong but its an open network signal and the free AVG on my tablet doesn't like it and shuts down my internet explorer!, I can't seem to find where i can swith off this action or if I can at all, any advice about this would be appreciaited.

Thanks in advance