This is a complex question but will try to compose it as simply as possible. Please read carefully.
On my Laptop, I set CCleaner to run at 0800hrs every Saturday using Task Scheduler. Ticked boxes, 'Run with highest privileges' and 'Run task as soon as possible after a scheduled start is missed'. As this was done on my 'Admin' account, SFSG.
Now I have added a 'Standard' account which is set to run on starting my Laptop. If I change the setting from 'Run only when user is logged on' to 'Run whether user is logged on or not' ( it asked for my password and I entered it). Will CCleaner do its work on both accounts ?
In my Admin account, CCleaner needs permission from UAC but not on my Standard account (UAC default setting on both accounts).