I am using below code to find find no of slides in .ppt,.pptx and .pot file .
Microsoft.Office.Interop.PowerPoint.Application pptApplication = new Microsoft.Office.Interop.PowerPoint.Application();
Microsoft.Office.Interop.PowerPoint.Presentation pptPresentation = pptApplication.Presentations.Open(path, MsoTriState.msoFalse, MsoTriState.msoFalse, MsoTriState.msoFalse);
count=pptPresentation.Slides.Count;
It is working file in my system , but online it is showing error :
Retrieving the COM class factory for component with CLSID {91493441-5A91-11CF-8700-00AA0060263B} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).