What are these files, how do I get rid of them  

clayto said:

Thanks for all the suggestions. I got rid of the files, whatever they were. I removed them one at a time with IOB file wiper which 'smashed' them successfully. After a few days they have not returned. The strangest thing is that despite each file being shown to be zero bytes, as they were deleted the read out for each one showed hundreds of folders were being deleted and thousands of files! So I was afraid something substantial wold be missing from my PC --- but not so, it seems. I am mystified.

Looking at your pic again (What are these files, how do I get rid of them) they look like folders, not files. The folders may have had nested folders with files. That could account for the "hundreds of folders were being deleted and thousands of files!"

And, can't tell now, but all those files could have been orphaned symbolic links. That would explain "zero" sizes.

It could be the folders were part of an update to the WinSxS folder, that is the most nested folder structure in a Windows install and several of those folders can be empty or contain 0 byte place holder files. I should imagine there was an issue cleaning up the temporary folders after the update.

clayto said:

I now suspect it is possibly the result of my not having unchecked 'wipe empty space' in the new version of Bleach, as I normally do. As I understand it, wiping / deleting without trace etc. is achieved in various programs by saving characters (zeros or whatever) repeatedly to the target ie. over-writing. Is this how 'permanently removing' files works in the Recycle Bin? The files did come back briefly in the Bin but this time emptying the bin seems to have worked. completely 'removing' them.

In general, "Wipe Empty Space" in any cleaner is a forensic process to remove the ability to piece data back together. Usually done if giving or selling a drive. For security.

Caution doing this on a regular basis in an SSD, more writes, more wear and tear.

Far as the recycle bin and emptying it. That is not by default a forensic delete, data can be recovered by various recovery tools widely available. If you want to empty the recycle bin and be assured the data is irrecoverable, take a look at this Tutorial by Shawn on how to add Secure Delete to the Recycle Bin.

Add Secure Delete to Recycle Bin Context Menu in Windows 10