I downloaded the lpk for USA Zip Code Points , and it worked great. Next I tried to download the lpk for USA Zip Code Boundaries ((http://www.arcgis.com/home/search.html?q=zip%20code&t=content), and the sdc file seems corrupted. I can see the sdc files in Windows Explorer, but I can't see them in ArcMap 9.3.1 to reference them to the associated layer file. Am I making an obvious mistake? I am using ARCInfo 9.3.1.
Due to the larger size of the USA Zip Code Boundaries layer package download, you will need to have Service Pack 1 & 2 and Service Pack 2 Quality Improvement Patch installed when using 9.3.1. Without these patches, the larger layer packages may download but will be unsuccessful.
These Service Packs and Patches can be found here:
ArcGIS (Desktop, Engine, Server) 9.3.1 Service Pack 1 ArcGIS (Desktop, Engine, Server) 9.3.1 Service Pack 2 ArcGIS (Desktop, Engine, Server) 9.3.1 Service Pack 2 Quality Improvement Patch
I's also suggest installing the following patch from the same page so that you can successfully download any layer packages created using Desktop 10.0 software:
ArcGIS 9.3.1 Service Pack 2 Desktop Layer Packaging Patch