Originally Posted by meme
At least on Vista, you also need to set it to show system folders since the 'system' folder is being seen as a system folder to Windows.
Rie142 - for the couple of collections you get that you don't expect - what does it say about them in the report that is displayed when you run Preview? It should indicate if they are from Calibre or on the Kindle already. If they are on Kindle already you can just use your Kindle to manually delete it after making sure you don't want it.