The Spectrum Information Window will always show the filename and other relevant information (source name, observation date, exposure time, etc) for the currently displayed plot. If multiple spectra have been loaded into profit, any of these can be brought forward into view by using the Spectrum menu, in the Menu Bar.
To load a new spectrum, use the ``Open'' command under the File menu. This will present a standard file dialog box, allowing any file to be selected. Currently, profit can read OGIP standard spectrum files (often called ``pha'' or ``pi'' files), as well as properly-formatted ascii text files. We discuss each type of file here.