When creating PowerPoint files with Create, specifies which file format to use.
Create
enum FileFormat
Enum FileFormat
Presentation pres = ppta.Create(PowerPointApplication.FileFormat.Pptx);
Dim pres As Presentation = ppta.Create(PowerPointApplication.FileFormat.Pptx);
Name
Description
Pptx
PowerPoint 2007 and 2010 xml-format files, with the .pptx extension.