The Best Free File Manager Apps that can be run from USB
CloneSpy is a Freeware Tool that can be used to "Find and Remove Duplicate Files", clean your computer of unnecessary clutter, and free up drive space. Created by Marcus Kleinehagenbrock, this tool can detect and list files that are either exact duplicates, have same file name, have same size, or are zero bytes long.
UltraExplorer was designed to be the ultimate file manager and can be used to replace Windows Explorer. It sports many additional features such as a customizable user interface, favorites window, filter window, history window and even comes with the option to run the command line window from the current directory.
File Renamer is a Free Portable Software created by Stefan Trost that can be used to Rename Multiple Files simultaneously. Multiple file renaming options are available with File Renamer, enabling users to number files, find and replace words numbers or characters in files, add characters to the file names and more.
SE-Explorer is an awesome Free Portable File Manager and Explorer for Windows (Windows File Explorer Replacement). SE-Explorer features a tabbed interface with dual pane browsing, a file search option, a file size scanner to help locate the largest files, resource (hex) view for exe files and icons, syntax highlighted text viewer, built in web browser and much more.