Portable - Exiftool

where software installation is restricted.

exiftool '-FileName<DateTimeOriginal' -d "%Y%m%d_%H%M%S%%-c.%%e" *.CR2 exiftool portable

ExifTool is command-line only . There is no GUI. However, several third-party GUIs (like ExifToolGUI) can be made portable alongside it. where software installation is restricted

Here is why the portable variant is a game-changer: ExifTool is robust

Download and unzip the archive, then double-click exiftool(-k).exe to view documentation or drag-and-drop files onto it to view metadata.

Unlike graphical user interface (GUI) editors that often crash or fail to write to specific proprietary RAW tags, ExifTool is robust, comprehensive, and incredibly fast. It is the "Swiss Army Knife" of metadata manipulation.