There could be a little more to this.
MS say :-
...Restore points are created automatically every day, and just before significant system events, such as the installation of a program or device driver. You can also create a restore point manually...
Alex Nichol MS MVP (Windows Technologies) answered the following Q re: XP
>How do you set when XP creates a Restore Point its automatic restore points? I have a PC and the restore points are further apart than I would like. I would like them every day.
They ought to happen every day *if* there is a suitable idle period for
the process to start. What happens is that 24 hours after the last one
Task Scheduler (which must be enabled) sets SR to look for a period when nothing has been going on for (by default) 15 minutes. It then triggers the making of the next point. This waiting for an idle period means that constant CPU background tasks will prevent points being made. You can reduce this 'ThawInterval' for needed idle time from the 900 seconds if you want by a registry edit of the value at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\System Restore ...
I have found no daily 'System Checkpoint' for a particular day if there was no 15 min mc idle period during that day, 24 hrs after the last time based checkpoint - ie. mc on - use in some way - shutdown after use. So the 'missing' point - by time and date - never existed.
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