comparing two ms word file

I'd see if there's anything in this thread which helps:

https://social.msdn.microsoft.com/forums/vstudio/en-US/b7f4b480-ca1c-49a1-a2ea-b1d1cf5ad56b/how-do-you-compare-two-word-documents-in-c

As the solutions proposed here are using Word Interop, you will of course need to add a reference to the Microsoft Word object library (under the COM tab) to your project.

Refer this it may help you

http://stackoverflow.com/questions/4388355/comparing-the-contents-of-two-huge-text-files-quickly