Right before the scheduled time for production upgrade from SPS 2003 to MOSS 2007, my customer's SPS 2003 production environment was down. The database server was running on SQL Server 2000. The DBA told us ALL the SharePoint datababases just disappeared overnight and they didn't have any script to track who deleted them or it's virus or some other kind of intrusion (unbelievable?!).
Anyway, I was asked to help with restoring the SPS 2003 farm using all the database backups including the CONFIG database, but restoring a CONFIG database doesn't work most of the times since it can be easily out of synch with the content databases (refer to the SPS 20903 resource kit http://www.microsoft.com/technet/windowsserver/sharepoint/V2/reskit/c2861881x.mspx ). That's also my customer's case. They were seeing all kinds error message when trying to navigate through portal site - "invalid configuration database (offline)", etc. So there's no point of trying to fix that, we just decided to rebuild the configuration database in stead.
The following steps decribe how I restored the SPS 2003 from the SQL databases that were restored from the backups in the tape: