Using interop for Office is generally seen as a "no-no" in ASP.NET. You should rather use the OpenXML libraries provided by Microsoft. You can read more about it
here[
^]
Quote:
Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application or component (including ASP, ASP.NET, DCOM, and NT Services), because Office may exhibit unstable behavior and/or deadlock when Office is run in this environment.
Microsoft does not reccomend using automation in ASP.NET:
MS Support[
^]