I recently moved into a new house that I share with multiple other people, and which has WiFi supplied by the landlord. My Windows laptop always has a strong signal with a fast connection, but my iMac (running 10.9.5) almost never does, even though it never had any problems at my old residence. It will say that I'm connected with maximum signal strength, but whenever I try to load a web page it will say that it cannot be reached, as though the internet were not connected at all. The WiFi will occasionally work for brief spurts, but this will never last for long, and it will usually not connect at all. I've tried numerous things; I've unplugged the router to reset it, I've turned the computer off and unplugged it for awhile before turning it on again, I've deleted the WiFi information and then added it again, I've ran a diagnostic... nothing has worked so far. I have no idea why my laptop connects perfectly fine but my iMac doesn't, nor do I know why it says it has a strong signal but won't actually load anything. I haven't fiddled with the router yet since it's not mine, but I can probably do so if someone can give me a lead.