He actualiazado recientemente a la versión 3.20. En el fronted no aparecen los formatos ppt y pptx como permitidos. Sin emargo en la configuración aparecen. No se que puede ocurrir.
Hi
I have used Google translate to understand you query as my Spanish is poor. So excuse if I have misunderstood.
Your question is I believe that you want to upload say ppt and pptx files into a Download
You can upload any type as controlled from the front end by the User Group Settings
See http://www.jdownloads.net/documentations/item/which-file-types-can-be-uploaded-from-front-end in the documentation
Colin