Turning off system restore destroys ALL the previous restore points.
Frankly I've never had much faith in system restore.
I tend to create a "clone" of the installed HDD, OS and all data after I've completed system setup.
the computer gets cloned again after a week of trouble free operation
after two weeks it is cloned again this time overiwriting the first clone
after a month the earliest clone is formatted and the latest clone "archived"
It's kind of a brute force method, but it saves time, eliminates virtually all user frustration and keeps me from bouncing computers across the lake just to count the bounces
On my personal desktop I clone my OS drive weekly
as for when to "plow it under and replant"?
I tend to believe that major system corruption is often the result of a hard drive issue. even if hard drive errors are "soft" errors the damage they do to the data is cumulative and usually irreversable.
the drive itself may be mechanically fine, but...
Basically there is a time for wiping the chalk board with the eraser and there is time to get a bucket of water and give it a thorough cleaning
Frankly I'm a firm believer in simply setting the suspect drive & OS aside
and soing a system install on another (NEW) drive then doing data recovery on the old one while it still works.
In effect getitng another blackboard and copying the important details after You've done a clean write
on the new one
because IF the drive is the issue you could lose everything....
there are two kinds of hard drives, those that have failed and those that will fail
If I were you I would spend my time backing up anything that isn't easily replaceable,Copy pictures, documents, music and video to backups.
then copy your browser favorites
Your drive might not be failing, if it isn't you made some backups.
If it IS failing and you don't....
In IT being paranoid about data preservation is a job requirement.
""DATA" preservation includes the OS installations"
even if you are only doing IT work for yourself the rules of the game don't change