Class not registered error when creating Excel workbook in C#

Question

When I try to access an Excel spreadsheet using the following code I get a \"Library not registered\' error when defining the workbook object wrkbuk using C# from Visual Studio

Answer 1

We had the same problem.

Our setup is like this :
Office 2010 : Word and Excel but Office 2013 : Outlook

We ran the installation program for Office 2010 and choose the repair option. After that, all the wrong keys in the registry for Word and Excel were deleted and the problem was solved.