We created a folder in My Documents called Fast File (any directory can be used) so our source and destination drives were both C:

Once the drives have been established, click on Choose Directory and your directories will start to appear in the right-hand panel. As soon as you see the directory you want, or the parent directory (the folder inside which the folder you want is located), you can click on it (no need to wait until the entire contents of the computer are on display if it comes up in the early part of the list) and show the application where you want recovered files to be put by selecting it and clicking Done. The interface will switch back to the first view.
File>Scan Source Drive will initiate the process of listing everything on your hard drive. If/when you see the file(s) you are looking for, you click on Options>Copy Selected Files and you will see 'Finished' in the Current Status dialogue box when the files have been copied to the folder you chose. It could not be simpler!