We've been running Access 97 for some time now, we have some 300+ DBs in it.  
Some are production grade systems that cannot be easily upgraded due to a
swath of custom programming.

However, we have some that NEED to be upgraded to memory and performance
issues.  We want to jump into Access 2003 but maintain Access 97 for as long
as necessary as we migrate all the databases over.

The risk is that if a user attempts to open an unconverted DB using Access
2003, they will be prompted to convert it.  It's way to easy for a user to
get click-happy and convert it.  Then bam ... the database will be unusable
either because many people will not have yet converted to Access 2003 or the
DB simply won't convert THAT easily.

What I want to do is prevent the users from having the option to upgrade the
DB.  I would rather if Access simply said, "Sorry, can't open an earlier
version of that database."  or something to that effect.

Is there a hidden switch or option somewhere that we can configure to
prevent the upgrade???