Replaced the internal hard drive (in order not to damage further whatever data might be still remaining on the old one).
The new one - Seagate ST2000VM003 Video/Pipeline HD® drive.
2TB to avoid some possible problems with a larger one.
It's description says: 24×7 operation for always-on demands DVR devices.
So the question is: should I keep it always spinning? Most of the time completely unnecessarily.
To avoid high number of start/stop cycles.
So far so good. Except that I immediately encountered a very unpleasant "improvement" in Hades: "stop recording" is no longer the default top choice but moved in the list to the 8th position.
So, instead of directly pressing twice on OK, now I have either to use the UP arrow 3 times first, or to find and press #8 and then to move the finger down to OK.
I hope it is possible to configure that order somehow and to have "stop recording" as the default selected choice as it used to be.