One of the Black Arts. Routers and dongles and for that matter those mini pci WiFI nics are all PITA to get going in a reliable configuration if you happen to use more than a single WiFi network. In the course of a single day my laptop probably changes network about 5 or 6 times, from home to work and back again. None of these changes happens smoothly always something pops up, usually a yellow exclamation mark triangle informing me there is no internet connection, which magically disappears about 30 seconds later. Must be the card/configuration I hear you say, maybe but I get similar little annoyances on my tablet and my phone. The tablet will occasionally go into an obtaining IP address loop which it never does until I reboot it, sometimes tempted to do this with my size 12s I might add. My students all have Apple MBA and if they don't reboot their laptops when they come into the building then they get no internet connection, so the little foibles don't seem to be isolated to Android/MS kit. Whatever the reason I can safely agree with others on this forum that WiFi is just a barrel of spiders to an arachnophobe in terms of friendliness to its users, and 15 years or so experience of using and configuring routers just shows how messed up and consumer unfriendly a consumer device can be.