I have a wifi home network with several devices (laptops, all but one are Windows 7, and a wireless printer) connected through a dsl modem/router (a NexusLink 5631) to each other and to the internet. The laptops can all access shared folders on each others' hard drives, and all can print wirelessly to the printer.
Until ... after a few days of happy camping suddenly none of the devices can 'see' each other (can no longer find any other device on the network) and none of the laptops can access the wireless printer. However, internet access is never disrupted; each laptop can still happily surf the net no problem.
I am somehow able to rectify the problem by rebooting the dsl modem/router, updating the connection settings on the printer, going back and doing it again, turning round three times and twitching my nose ... after fiddling for a while to no good end everything comes back as it should. And I don't know why.
I have contacted my dsl provider (Frontier, in Ohio) who own the modem/router and they say it's nothing to do with them. As long as I have internet access they're not interested.
I called them because, interestingly, all this only happened when I switched from my old) cable provider to the dsl provider. When I had the old cable modem/router this issue never occured.