Files stored on my pendrive have gone missing, but upon checking the device properties, it seems that the some space is being occupied.
Check whether the files are not in hidden mode.
Click on Start --> Run --> Type control folders and press Enter.
"Folder Options" window will be opened. Click on "View" tab --> Select the option
"Show hidden files and folders" and uncheck the check box "Hide protected
operating system files" and click on OK.