Thanks. I see in that dropdown list that the colors we were used to are now called "retro." Sounds disparaging but looks OK to me.
To cut to the chase, I will interject here that I evidently forgot that I was making a recording and shut down the system... The speculations and observations below ultimately lead to that conclusion.
- - - -
The state of the system... well, I will check Windows Events. I set up MyHD to shut off the computer after my last capture, and this was my last capture. I imagine the capture didn't end, so it didn't shut off. However, the machine is set up to shut itself off in any case a few minutes after 1:00 AM, so it would be off in any case (and was off). I'm on my laptop now, so will check the HTPC's Events Log later. I don't know that it will give me any info that's helpful, though.
Edit: On my HTPC now, and looking at the Event Log I see that there was an event at 7:36 PM Sunday night (when the recording stopped). The event says simply that the Event Log stopped ("The Event log service was stopped.")! However, I don't see the customary event at 1:08:05 the following morning, being the automatic shutdown, so I presume that the machine had somehow shut down about 7:36 PM Sunday ??? It was not on when I came back to the machine Monday morning.
I suppose it could have been a very short power failure. Long enough to shut down the PC but not long enough for any of the systems in my house to "report" it (i.e. digital clocks flashing 12:00). Well, it's a theory. I wonder if the Event Viewer reports Event Log stoppage in the event of a blip power failure... Guess I can try that experiment.
Edit: I switched off power to the HTPC as an experiment and see several event log messages, none of which mentioned the Event Log service stopping. So I have to assume that's not what happened. Another thing has me pretty confused. If the PC had turned off, it would have turned on again about 11:54 PM in the evening, because the PC's BIOS is configured to turn on the PC daily at 11:54 PM. I see no record of that in the Event Log. This is not understandable to me. If the PC had not been off, it would have shut down at 1:08:05 the following morning and again there would be an event log entry to that effect. There is not. But the PC was off a few hours later. I'm flummoxed. The only explanation I can think of is that I turned off the HTPC, and switched off power to it so it wouldn't automatically boot later in the evening. Argh. I don't recall doing that but the facts would suggest just that. Yep. "User error."