Microsoft Visual Studio 2010 Tools For Office Runtime -x64- Link -

This runtime supports solutions built for Office 2010, 2013, 2016, and newer versions. How to Install the Runtime

Conversely, if you have 32-bit Office installed on a 64-bit Windows system, you would actually need the x86 version of the runtime. System Requirements and Prerequisites microsoft visual studio 2010 tools for office runtime -x64-

The bitness of the VSTO Runtime must match the bitness of the Microsoft Office installation, not necessarily the Windows operating system. This runtime supports solutions built for Office 2010,

A set of unmanaged DLLs used by Office applications to load the runtime and your specific solution. Why You Need the x64 Version A set of unmanaged DLLs used by Office

Managed assemblies that facilitate communication between your custom solution and the Office application.

Before installing the VSTO 2010 Runtime, ensure your system meets these criteria:

You must have the .NET Framework 3.5, 4.0, or newer installed first.