I sorted out cleaning software a long time ago and rarely look at anything new, but a short time ago I read a review of
KCleaner.
As it is portable and also has an 'Analyse' mode when run manually I gave it a try.
To my surprise it turned up quite a few files on both XP and 7, the majority of which were MS Update related.
Having looked through the list to make sure there was nothing that was needed I let it run and have had no problems.
I would not recommend running it automatically, at least until you have sorted out what it finds.
Nor do I think it is something worth running frequently, CCleaner plus CCEnhancer find most of the regular stuff.
But I definitely think it is worth running after installing MS Updates each month.