So simply uninstalling CCleaner was enough to allow Office to be launched again.
That is telling and I think I know what the problem was.
I think that you had run the Performance Optimizer in CCleaner and (maybe inadvertently/unknowingly) put Office into to sleep mode.
Once an app is in that mode it should 'wake up again on demand, however…
We have had a few people say that once they did that with Office then their Office would not wake up again when launched.
(It seems to be different for different Office versions, and different computers).
The usual solution if they still wanted to use PO on apps other than Office was to manually go back into PO and ‘Wake Up’ Office manually (and not put it back into sleep mode again).
Or they could ‘Wake Up’ everything and ignore PO from then on.
