InstallAware

My problem is that I first installed my first database with the first installer and then when I try to use the second installer that I just created; it gives me an error message saying "Another application has exclusive access to the file ' path \\mydatabase.mdf'. Please shut down all other applications, then click Retry again". So what I have done to allow the second installer to work is to take offline the first database in SQL Server and that works properly. But still the second installer automatically delete my first database out of the SQL server. I am wondering if there is any way to prevent this problem since my clients will have to install many databases into the same machine.

Thank you in advance from your client.

Ricky, can you provide with more info on the projects of first and second installers, especially for the DB creation/deletion. Especially the way of how you create DB's in firsr and second installers.
Do theses installers have different Product Codes? Maybe the second installer runs the Uninstall for first installer?