You can view or display a MS Word document using GroupDocs.Viewer for .NET API. Please note that this document viewer API is back-end, UI-Agnostic. Hence, you could implement or integrate it in any .NET application without any third party tool or software dependency.
Yes, please have a look at these minimal system requirements to get started with the API. Internet is not a required thing in order to render or view the Word file.
However, you can load a document from multiple sources.
As mentioned earlier, API is UI-Agnostic. You can develop a customized navigation or tool-bar. Please have a look at this video demo and these open-source example projects.