Select File > Settings and then choose General in the left list.
Most of these settings do not need altering to work with Pirana.
Name of researcher — Name to display as the researcher.
Alternative data-file directory — Location where Pirana should look for model input data files.
Prefix for models/runs (filtered out in Pirana overview) — Prefix to prepend to any model or run file names.
Start Pirana in — Directory/project to load when Pirana opens. Choose from:
the most Recent directory in which you were working with Pirana,
the most Recent project that you had open, or
the Pirana Home directory.
Automatically backup models and results (model archive) — When checked, copies models and results to a backup folder. (Each folder containing models has a sub-folder for backup purposes.)
Automatically cleanup folders for model runtime — When checked, removes runtime files after run completes.
Close console window after run finished — When checked, closes the console window automatically after a run completes.
Disallow overwriting of output files once estimation is done — When checked, only allows a run to be executed once (requiring creation of a new model to re-execute).
When unchecked, you can re-execute the same run multiple times and Pirana will create a new subdirectory, sequentially numbered, for each run’s outputs. It will also copy the main results to the root folder directory, which makes it (the most recent results) readily available.
Show model execution log from all folders — When checked, displays the icon 
for listing all executed runs in all folders.
Enable Pirana web server — When checked, allows models to be run by Pirana through a web server.
Use any free port — When checked, allows Pirana to choose any available port.
Port to start web server at — Port for the Pirana web server.
Enter “0” to disable the Pirana web server, “-1” to automatically choose any available port, or any valid free port number.