Unable to cast COM object of type 'Microsoft.Office.Interop.PowerPoint.ApplicationClass' to interface type 'Microsoft.Office.Interop.PowerPoint._Application

My team have been struggling with COM Component issue for about one week, it almost frustrated the developer, me and project manager. Uff.. after intense amount of googling and trial method, several time repair and installation of office, the problem was still bugging all the team members. Finally the issue was resolved with couple of settings in Registry. The real cause of the issue was a mystery. Finally we succeeded to identify the reason for the issue and then killed the exception.

Exception thrown by the system:-

Below is the most boring exception frustrated me every time when I debug the code

System.InvalidCastException was unhandled

  Message=Unable to cast COM object of type 'Microsoft.Office.Interop.PowerPoint.ApplicationClass' to interface type 'Microsoft.Office.Interop.PowerPoint._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{91493442-5A91-11CF-8700-00AA0060263B}' failed due to the following error: Error loading type library/DLL. (Exception from HRESULT: 0x80029C4A (TYPE_E_CANTLOADLIBRARY)).

  Source=Microsoft.Office.Interop.PowerPoint

Read the entire post at :  

C# PPT to PDF-Unable to cast COM object of type 'Microsoft.Office.Interop.PowerPoint. ApplicationClass' to interface type 'Microsoft.Office.Interop.PowerPoint. _Application