After some valuable help from the fine folks on this exchange, I managed to get two desktops and a laptop networked using a Linksys wireless/wired router. The
laptop has a wireless NIC plugged into a port, the other two computers are connected to the router by cable.
It's been working flawlessly for three wonderful weeks. Then suddenly today, I get a "network path not found" error when trying to access the desktops from the laptop.
Then it came back and I had full access again ... then it was gone. Back. Gone. (You get the picture).
The two desktops can see/access both each other and the laptop -- it's just the laptop with the problem. Everyone can ping everyone else.
The only thing I did differently today from other days, was that I unplugged the wireless NIC from the laptop briefly, so that I could take the laptop on the road in its case. From what I've read, though, the symptoms don't suggest a bad NIC, since everyone can ping.
Ideas? The sordid details of the earlier heroic networking effort are here, in case anyone is interested: