Hi Louis,
Your migration path from 2009 to 2012, will need to be one of the following methods.
Back up Vault 2009 migrate to 2010 by running the installer for adms 2010. Allow Databases to migrate to 2010. Back up once more then upgrade SQL 2005 to SQL 2008 SP2 or SQL 2008R2 SP0 then migrate to ADMS 2012 by installing from the installation media.
You can also perform the upgrade from 2009 to 2011 then 2012 following the same back up steps and SQL migration steps once you've successfully migrated to 2011.
For SQL Migration steps, please see the 2011 Advanced Configuration Guide beginning on page 4.
Once you have installed ADMS 2012 DO NOT run ADMS. We recommend you install the Cumulative Multi Issue Hotfixes only. Once they have been installed, open ADMS 2012 fro the first time. Allow the databases to migrate.
Please let us know if you need more detail.
As always, prior to any upgrade installation, we recommend testing the migration steps using a non production server, to ensure you do not run into any unexpected issues with migration. Also, with every upgrade, we recommend a full review of the readme prior to installing software for important installation instructions, hardware and software requirements, etc.

Ron Smith
New Product Introduction Manager
Autodesk, Inc.