First, some background. I have a GoClever Orion 785 Android (Jellybean 4.2.2) tablet which I have been happily using for over a year. I am using an external SD card which I use to store data (music/pictures/docs/pdf). For cutting/pasting files I use the ES File Explorer app that was supplied with the tablet. I periodically connect it to my laptop via the USB lead to back up the data. After over a years' use I noticed it becoming sluggish and more unstable, so I performed a factory reset and reinstalled/updated the apps I use most. There was a marked improvement.
Now, when I connect to my laptop, and view the external SD card with Windows Explorer prior to backing up, I see that all the folders are shown multiple times (around a dozen or so copies). Looking in these folders, the files icons primarily show as blank - as if the file type is not recognised. It is almost as if these are archived backup versions. Consequently, it takes some time to locate the genuine folder for backup purposes. These duplicate folders do not show up when viewed within Android using ES File Explorer. However, most of the images shown in the Gallery are blank - presumably picking up the file copies. The same occurs when viewing the music files within ES File Explorer - but they cannot be deleted within that app.
As all the files were backed up, I decided to try deleting the "archive" folders within Windows Explorer. Not a success, as only a handful of blank images/videos at all are visible within Gallery, and none at all within ES File Explorer on Android. I note the latter now has a Recycle bin, but I have been emptying this, and I have since tried disabling this option.
So - my question is, can anybody suggest what is causing these duplicates, and how can I stop it recurring? Hopefully before I start accumulating more data.