You can define a Home view for a model so you can restore a familiar view when you use the navigation tools.
The Home view is a special view stored with a model that makes it easy to return to a known or familiar view. You can define any view of the model as the Home view. The saved Home view can be applied to the current view by clicking the Home button above the ViewCube tool or from the ViewCube menu.
When you open a drawing that was created in a release earlier than AutoCAD 2008, the extents of a model are used as the default Home view. Drawings created with AutoCAD 2010 have a Home view defined with a Top/Left/Front orientation. While you can use the Home view to navigate back to a familiar view, you can also use it to generate the thumbnail preview when you save a model instead of using the last saved view.
The Thumbnail Preview Settings dialog box is used to control the thumbnail preview for a drawing when saved (the Home or the last saved view). Along with defining which view is used for the thumbnail preview, you can also set the Home view back to its default view.