SOLUTION!
First, make CCleaner save its settings to an INI file (rather than Windows' registry).
Scond, remove the check on "cleanup on computer startup".
Third, make a registry entry as follows:
I did something similar, excepting :-
1. I added a check to the option "Run CCleaner when the computer starts"
2. I therefore did not touch the registry.
I did NOT like the results, so I reverted to NOT using an INI file.
When the INI file is NOT used, the configuration is held in the user profile.
My daughter's profile has a TAME configuration so that nothing bad can happen, and nothing important can be lost.
Because I have 30 years experience as a professional Real Time software engineer, I risk a more aggressive configuration, but I always "analyze" and review every file on the hit list before they go.
In Options / Include I stipulate a few extra temporary file locations to be purged, including some within my user profile e.g. C:\Documents and Settings\Dad\Local Settings\Temp\*.*
My profile will not permit C:\Documents and Settings\Daughter\Local Settings\Temp\*.*,
and my daughter's profile does purge her Temp but not mine.
When I tried the INI file approach I found it was a one size fits all thing,
i.e. we both have a TAME configuration or an AGGRESSIVE configuration.
Additionally, trying to stipulate two user profile temporary folders is a hurdle I gave up on.
I concluded that that INI file would only work if there was a separate INI file in each User Profile, and since CCleaner.exe requires the INI file to be in the same folder, that would require installing multiple instances of CCleaner.exe in multiple user profiles. This was some time ago, so the situation MAY have altered.
Regards
Alan