To Save a Drawing With Layer and Spatial Indexes

1. On the Quick Access toolbar, click Save As. Find
2. In the Save Drawing As dialog box, choose Tools Options.
3. In the Saveas Options dialog box, under Index Type, select Layer, Spatial, or Layer & Spatial and click OK.
   Note: If you are saving a partially open drawing that does not already contain layer and spatial indexes, this option is disabled.
   
4. In the Save Drawing As dialog box, click Save.