Delete and create a new instance of SQL

Well since MSDE does not come with a gui interface to manipulate databases, try using osql. Once you attach to the system, try issuing a DROP statement. Sorry, but the system that I am on currently does not have MSDE, so I can not give the actual code.

It depends on whether you have the admin login or admin rights to the MSDE server or not, and whether you have any SQL tools or not.

You can get a free copy of the SQL tools from Microsoft by going to: http://msdn.microsoft.com/vstudio/express/sql/download/

If you have either the admin ("sa") password for the instance of MSDE, or if MSDE is configured for Windows security and you have a sysadmin or network admin account, you can then connect to the database using the tools and issue a drop command.

As for creating a new instance of the database, if the Autodesk Vault program has the ability to create the database, use that. If not, before you drop the database, create a "create script" for the database using the SQL tools and use that. (If any of the tables are supposed to have data in them on install, the create script won't do it.)

Of course, before you drop the database, please back it up.

If you get the SQL tools and can connect to the database, but aren't sure how to back it up, how to drop it and how to create a "create script", feel free to ask for those details as well.