Ok, tell me what network card do you have in your second laptop (I mean this one which works wrong) and did you use external netword cards? They can be a solution for you. I recommend TOTOLINK network cards.
Maybe you should reinstall your network card drivers to new ones?
Tell me if it helped you.
I have 2 laptops, one is working on Wi-Fi and the other seems to go on and off even if I have correct internet signal, any idea what could be wrong with that laptop