Are these DLL's below are included in .Net Framework Redistributable?
DocumentFormat.OpenXml.dll
Microsoft.Office.Interop.Word.dll
Thank you
No. You can get DocumentFormat.OpenXml.dll from the Open XML SDK 2.0 for Microsoft Office. The download is here.
The Microsoft.Office.Interop.Word.dll assembly is a COM interop assembly. It is automatically generated when you use Project + Add Reference and select Microsoft Word from the COM tab. That won't happen when you've got the Office PIA installed, that's okay.