: The Visual Studio 2010 Tools for Office Runtime page provides the vstor_redist.exe installer.

: It provides a communication layer between Office applications (like Word or Excel) and the .NET Framework, allowing managed code to automate and extend Office functionality. Core Components :

—or VSTO for short—is the unsung hero (or lingering ghost) that allows your Excel spreadsheets and Word documents to do things they weren't originally designed to do. What Is It, Exactly? Think of VSTO as the

Specifically designed to run Office customizations within 64-bit editions of Microsoft Office .