From the Image screen, you can import and export presets from the Toolbar (Preset tab). Or use the right-menu when selecting a preset in the Preset window.
But it's easier to bulk copy the same XML files from "C:\Program Files\NTLite\Presets". To delete or copy files into the Presets folder, you must be Administrator (it's a security measure to prevent casual tampering). Copying files out doesn't require any special privileges.
You can also replace license.dat and settings.xml from your backup, before running NTLite on the re-installed PC.