@Hans1
On that link you posted MHP etc... the writer (Ken Blake) responds to a commenter asking what he should be doing, if not running a reg cleaner:
"But there are many things you can do in this regard that are
completely safe. For example, you can run Disk Cleanup and do all of
the choices there. No problem and it gets rid of some things you don't
need, thereby saving a little (usually very little) disk space.
Similarly, you can run CCleaner, which does a lot of the same things,
perhaps a little more thoroughly. CCleaner is safe to use, as long
as you don't use its registry cleaning functionality, which is not
safe."
Interestingly he also recommends Avast, amongst other things.