Hardware again !System wrote :
BSODs with varying messages are often a sign of hardware issues.
All points to replacing my NTFS drive with new SDD drive (and Windows license won't be a problem).
And my very last question (to System or anyone else):
is there a software tool out there that can diagnose and confirm the hardware problem that we are suspecting here ?
I have several Disk Check programs (e.g. Puran Disk Check) that all scan my C drive as "healthy" (no errors).
Also, drive health programs (e.g. Hard Disk Sentinel) do not seem to show any problems.
Thank You all for your excellent thoughts.
I will change the title of this post now to [resolved], since the topic received a more than satisfactory answer.