There is an option to check to clean the 'Window Delivery Optimization Files'. When I check this, a warning notification pops up. I have attached a screenshot of the pop-up. What does this warning means. Should I be worried. Can anyone please advise me if it is ok to check this box and clean without any issues running windows 8.1 Pro.
Thank you very much Nukecad. Your response was very helpful. ?
Windows will clean them automatically after a while, or you can tell Windows to clean them manually.
Why CCleaner is warning you about clearing them I don't know?
It may be because previously CCleaner could clear the update files themselves - but Windows changed that way that those files are used after an update and so cleaning them was removed from CCleaner so that it wouldn't/couldn't clear those too early.
Then although it should be safe to clear the Delivery Optimisation files (at worst it might slow down the next update for you) CCleaner may have put a warning on just in case Windows changes how it handles those too.
I'd suggest that you leave it unticked and just use the Windows Disc Clean-up now and again, or ignore them and Windows should eventually remove them itself.
The warning does not seem to be expressing a concern - however why is it a warning?