I have the same problem periodically. The wifi will connect on the SG4 then all of a sudden the phone will tell me I have no internet. I try to reconnect, but it just does nothing, even though it says 'saved and secure'. I have tried diabling my wifi adapter in the PC, re-enabling it, sometimes that works. Or sometimes I reset the DSL router and that works (I have an app on the PC that lets me share wifi from ethernet). But far too often when this happens, nothing will help. The phone (and other devices) will not connect to wifi, so I have to restart the PC, or even do a system restore (!) to get it all working again. Very frustrating. For some reason, I think, the PC wifi gets changed in some way so the devices see it, but cannot connect. Any further suggestions are appreciated