Version 1 - Reviewed: January 2, 2012
The error that you get about missing interop files is usually the result of Office 2010 .Net Programmability Support not being installed. The interop assemblies are not a required component of an Office 2010 install, so they may not be installed. To install, either "Full" setup must be selected or "Custom" setup with selecting ".NET Programmability Support" for the desired products (for TariffShark, Word .Net Programmability support is needed).
There's also few ways to correct the problem after Office 2010 is installed:
You may need local administrator rights on your PC in order to take the steps outlined above.