contrary to what some sites have posted in the past, you cannot selectovely delete restore points.
you can delete them all
or you can delete all but the last one.
or through some effort, you can delete in sequence on;y the most recent, or the most distant, and forward or backward, in sequence
in addition, you can not save preferred restore points, as they are eliminated in sequence, over time.
eeach restore relies on the previous restore, and all restores before that...so even the os can only delete the most distant resote.
my favorite suggestion is to reduce the amoount of space available for system restore to be used in the first place