To open files in Autodesk Navisworks, you can either use a standard Open dialog box or drag and drop files directly into the Selection Tree window.
Autodesk Navisworks keeps a list of recently opened files (by default, up to 4 files are shown). You can open any of these files by clicking the application button . If you want to modify the size of this list, use the Options Editor (General node Environment page).
You can use the SHIFT and CTRL keys to open several files at the same time. This automatically creates a new “Untitled” Autodesk Navisworks file with the selected files appended together.
This feature is not available in Autodesk Navisworks Freedom.
For NWD files, it is possible to publish them to a web server, and then open them directly from within Autodesk Navisworks. You can start navigating the model even before the file has been fully downloaded. For this, 10 - 50% is usually sufficient. The greater the hierarchical structure of the model, the closer to 50% download is required. Similarly, the lesser the hierarchical structure of the model, the sooner you can begin the navigation.