pre to pptx conversion is most likely searched by users looking for a way to directly convert old Freelance presentations (.pre) to Microsoft PowerPoint, something that was perhaps doable with some old version of PowerPoint (to the old .ppt format), but will be a challenge using modern version of the software.
it might be easier to find old copy of Freelance somewhere on abandonware websites and export these to some exchange format that can be imported to modern tools.
Updated: July 31, 2023