This may have well been posted already, but who has time to read the entire thread. Imo, since I'm no computer guru, I do think it is power related b/c mine seems to shut off the internet only when I'm on battery power. I haven't found a setting that enables me to determine at what battery level it shuts down, but I'm still looking. I haven't lost it since I guessed this was the problem so every time it came back up I had restarted my computer. Next time, I'm going to just connect the power cord and try to turn off, then back on the wifi. God, I hope that works. I still HATE Windows 8.1.
I just changed the settings that gbcjr suggested^^ and hope and pray that works. I'll keep you posted if it doesn't...(If it does, I probably won't even think to come back here to comment). It makes sense.