How to: Install Office Primary Interop Assemblies
Install the Microsoft Office primary interop assemblies (PIAs) when you install Office.
To install the PIAs when you install Office
Ensure that you have a version of the .NET Framework that is no older than 2.0.
Install Microsoft Office and make sure that the .NET Programmability Support feature is selected for the applications you want to extend (this feature is included in the default installation).
By default, PIA’s are embedded in your solution when you build it so you don’t have to distribute PIAs to users as a prerequisite to using your VSTO Add-in or customization.