stellular :
Since none of the answers was a solution for my problem, there is no "best"
answer. However, I do sincerely appreciate all the responses looking to
help.
I've had the same issue - twice, now - over the years. Using Windows XP, reserving restore space only for the C drive and activating System Restore only there, I still lose my restore points.
A month ago I had to re-install XP completely and, as before, made regular restore points as I went. Today, after making another tweak, I made another restore point and, as I've been numbering them, checked back to see what number I was up to.
The answer is, apparently, Zero. No previous restore points existed any more.
Remember, this is a practically brand new install.
I've checked with anti-virus, anti-malware, anti-adware and goodness knows what else and each has come up with no errors. The error, it seems to me, is in MS implementation of the System Restore routine, whatever that may be.
I long to be corrected about this - and to find someone to answer the mystery, which has clearly affected many users and never been satisfactorily resolved, even by the most helpful and knowledgeable of respondent.
I begin to seriously doubt the value of this "facility".