There are some settings you can use to get comparing results:
The first is a Preset.
Comparator Fast always will run and use your last used settings, but also you can define those settings by yourself (in order to save time for you), so a preset can include your preferences about the From path (directory), the To path, and all other settings.
The second is a file specs box, where you can specify what files do you want to include in the search, as wildcard.
Example: the default is all files (*.*). If you want to search your