Hi Ashutosh,
You might like to explore the option of using the Word
Automation model on the server to perform these conversions.
Other than doing a TLBIMP on the MSword typelibrary,
MS Office also ships with Primary Interop Assemblies (PIAs)
that will allow you to use the automation model from C#.
To convert from .doc to .txt, open the exisiting document using the
Word automation model (I assume something like
Application.Documents.Open() - you can refer the documentation
to get the correct method), and then call the Document.SaveAs()
method tosave the document in the desired format (.txt in your case)
Regards,
Aravind C