The landlord where I live has recently changed ISP, and consequently had to replace their primary modem/router. As I am some distance away I connect through a satellite router which they also set up.
When they changed ISP and router, three PCs running Windows 7 and my Android phone all lost internet connectivity (they connect to the wifi perfectly well, but have no internet access), however two MacBooks that I have tried can both connect flawlessly. Even more baffling I discovered today that my work laptop, running Windows 7 and still showing no internet connection, can establish a VPN through the network to my work perfectly as well!
I am assuming this is some kind of DNS problem, and that the default configuration on OS X has somehow handled the change with ease whereas the Windows and Android config couldn't. None of the systems are using unusual settings - all are connecting using DHCP and their system defaults. There are no IP conflicts that I can see and the satellite router seems to be allocating IP addresses fine.
I have access to the satellite router and all computers and have restarted both that router and the computers multiple times to no avail. I have arranged to go and have a look at the landlord's router (the primary router and modem) tomorrow, but am at a loss for what I am going to look for to begin resolving this.