There are several situations that files or folders are unable to be deleted on a USB flash memory stick. It seemed nothing could be done to it just like it draw some kind of magic to get it protected from any change.
Usb drive won't let me delete files, how to delete file in usb that cannot be deleted? ( The truth: files can still be recovered after deleting with free pendrive recovery software.) Usually files can be deleted from usb drive by getting them selected, and then right click -> Delete or simple press the delete button on your keyboard to get them removed.
5 Free Tricks to Fix Files/Folders Can't Be Deleted from USB Flash Drive
