In the Title Bar of the PCB Configurator you can the units between mm (default) and Inch, if you have uploaded data then the units are set based on the data format provided.

PCB-Configurator-Units-Section

If you change any parameter in in any of the section, the Reset to defaults button will appear next to the Units. This allows you to quickly reset all parameters to their defaults.

PCB-Configurator-Reset-to-defaults