The things I thought might bring the hard drive on my main computer back to bootable life like writing a new master boot record or doing a repair Windows installation did not work; however, the drive itself was readable when I plugged it into an external drive connection. Before going to bed last night, I set the drive copying all of my My Documents files and other configuration data into an external storage device. That gave me a backup of just about anything I had been working on when the drive stopped booting. Then I went back to the previous clone of the drive, which I'd made just before Westercon. I installed the clone and the computer booted without a hitch, other than the installation was now a few weeks out of date. Next, I copied directly from the non-booting-but-readable drive all of the stuff in My Documents with more-recent last-changed dates. Fortunately, this wasn't a whole lot of stuff. Finally, I copied over the material from the backup computer that I'd done in the past week.
As far as I can tell, I seem to have recovered nearly everything, aside from possibly an odd bookmark or two. And, with all of my files backed up to the external backup device, later today I can set a new clone going, cloning the now-primary drive onto the non-booting drive and trying to boot from the clone -- this last to see if the drive is still physically sound.
While this is time-consuming and inconvenient, it's nowhere near as much trouble as it would have been to try and rebuild the computer from scratch. All of my applications are still running without having to reinstall them. That money I spent on a spare hard drive and a DriveClone license is well spent.
And because I once again have a computer that runs VPN -- it wasn't installed on the secondary laptop, whose primary purpose is to serve as the conduit for downloading sports and sometimes providing sound effects for Match Game SF -- I can again get to my company's network and can continue to work from home today, instead of having to make the trip today. That's a welcome relief on this first day back from "vacation."
pleased