The problem with PatrickLarson's "fix" is it disables the function of the preview pane. Thus is no more of help then simply turning off the preview pane and you wont get the error message in the first place.
Where I run into the problem on a daily basis is I have a lot of scans that are named (by default from my scanner) scan 1, scan2, etc.... I used to be able from windows explorer to highlight the document and see which scan I happened to be on without opening
the file. This allowed me to delete, rename, or move a PDF quickly, while knowing what doc I was working with. Now I have to turn the preview off, open the file, then close the file to do any of those functions. This is a result of the preview pane acting
as a proxy (file in use) now when versions prior to Windows 8 did not restrict manipulating a file that was being previewed if the file was not actually open.
Again, I don't know if this is a "file explorer" issue associated with windows 8 or an adobe issue (as adobe too has updated their software to keep up with newer versions of windows, but regardless, it has crippled the functionality of windows explorer (of
file explorer- what it is called now).
Patrick's fix does alleviate the error message, how ever it doesn't allow the preview thus in my opinion is not a helpful fix for my particular complaint.
And as other posts suggest- This problem doesn't have to do with disc clean up or other utilities. It is clearly a bug that quite honestly is hard for me to believe hasn't been recognized and fixed long ago. Certainly I am not the only person who uses
the preview pane to manage and clean up file storage.