We're back online with the PC. File it under "duh"... I can't believe that it didn't cross my mind as the FIRST thing to try, when we couldn't connect, was hitting the "reset" button on the modem.
I tried hitting "reset" today, when I realized I hadn't tried that, and what do you know? It worked.
Ooo, I'm aggravated with myself. I used to do freakin' TECH SUPPORT. Granted, that was 18 years ago, but still, one of the basic things to try is still rebooting or resetting the misbehaving piece of equipment; technology has changed a lot over the years, but THAT hasn't changed. See what happens when unexpected error messages appear? Even people who normally know what to do can get flummoxed enough to forget the basics.
And guess what? I get to restart the PC again today... we have a new security update that won't take effect until the machine is restarted. Now at least if the flippin' modem whacks out, I'll know what to do FIRST.
Pass the freakin' TUMS. I'm about to hit Control-Alt-Delete and go through the reset process all over again.