TreePad is fully portable, meaning it can run directly from external disk (such as: USB disk, pen drive, thumb drive, flash drive, memory stick, etc.) without the need for any installation. Just copy the TreePad program files folder from your harddisk to the external disk and plug this disk into another computer. Then start the program by double clicking on the executable.
You might want to enable 'Store settings in an ini file' before copying your TreePad program directory to the USB disk. Otherwise TreePad will still store its settings in the registry on the target computer. If you enable 'Store settings in an ini file' then TreePad will create an ini file in the directory of the program. If the next time TreePad starts it finds the ini file in its program directory, it will store settings in this ini file, and not the Windows registry.