Two days ago I booted up one of the desktop computers that I use only occasionally. I browsed to a web site, no problem. Then I tried to browse to another web site and got the "This page cannot be displayed message." Hmm, that site must be down. So I try another page and get the same message. Then I troubleshoot, going through all the things that usually fix problems like this. Nothing. Finally, I decide to switch from DHCP to a fixed IP address. Bingo. Ah, one might conclude, the DHCP service on my server must not be working. But none of the other computers on the network had this problem, which appeared out of nowhere on a single computer that had been working just seconds before the failure.
Then, yesterday when I disconnected my laptop from its hard cabling downstairs and tried to use the wireless connection upstairs, it said I was connected but nothing came through. I didn't bother trying to investigate this until this morning, and now have wasted a couple of hours without successfully determining the problem. When I unplug the ethernet cable from the wireless broadcaster and plug it into my laptop, I get a good connection, so a signal is reaching my broadcaster. I can communicate wirelessly with the broadcaster from my laptop by browsing to its IP address. But I can't reach the Internet wirelessly. I've tried the usual resetting of everything--the server, the wireless broadcaster, etc. I've tried using a fixed IP address on the laptop. Nada. I had been using the wireless connection without problems many times recently. This problem just popped up out of nowhere. Like life appearing out of nothing. Or a body bursting into flames for no reason. Bah.