Should i buy a hawkings extender for my home?

I have a few gaming systems and they all have wi fi built in.But they can't connect to my service,even when they're right next to the modem.I thought the systems might be broken but i was able to connect them to neighbors and relatives ISP.I even contacted my ISP but they can't fix the problem.So should i get a new modem or buy a wireless extender and try that out,because my systems are obviously fine.