I was just asked by a client how to convert a newly created GDB in ArcGIS 10 to one that could be read by ArcGIS 9.3. Before 10, I would normally do this by moving everything to a personal GDB and editing the GDB_ReleaseInfo table to have the values the older versions expected to see. This always worked great as long as your GDB was fairly simple without a lot of higher end features such as geometric networks or parcel fabrics.
ArcGIS 10 however has completely revamped the personal Geodatabase schema so the GDB_ReleaseInfo table does not exist and I have not been able to find a table that contains similar information. So this method will no longer work for converting back to older versions. ESRI recommends if you want to convert to an older version, you should create a new GDB using an older version of the software. Then copy and paste the data from the ArcGIS 10 GDB to the newly created older version GDB from an ArcGIS 10 install. This is great if you have a computer installed with the older version but what do you do if you don’t.
One option I found is to create layer packages. When creating a layer package it has the option to create one that is compatible with older versions of ArcGIS. Here is a link to the online help with more information. If anyone else has ideas or methods they use I would be interested in hearing them.
Tripp Corbin, MCP, CFM, GISP
Vice President, GIS/IT
ESRI Authorized Instructor
CompTIA Certified Technical Trainer
Keck & Wood, Inc.
(678) 417-4055 fax