Interacting with excel files in C# windows application

You are right Bhushan ,but the other reason behind preferring OpenXML is that my technical architect wants it . :)

Right, but only if you dont manage to dispose COM objects properly, If you follow standard practices - then I think wont be an issue for you.

Well, my apparent assumtion is that Interop hampers the performance in some way.

any specific reason why you are trying to avoid COM components?

Thanks Bhushan, I was thinking I could avoid dealing with COM by not using Interop .

As you said, its going to be a windows application and if you have office clients installed on your machine as well as on your target workstations then I think using interop makes more sense and its fairly straight-forward approach compared to other mentioned two.