kelleycomputing,
Typcially, you would need to get the software from your current vendor. What you find out, at some point, is that you will need to get your ARID moved over to your new provider; you can call Mitel about local providers.
Now, after I gave you the boilerplate answer there are other ways to get the software, but let me suggest that you get the System Administration and Diagnostics software and then get the DB Programming version for you system; 4.0.3.99. This way you know the software will work with the latest version of Windows as the software for version 4.0.3.99 may or may not be able to work with your version of Windows.
I will send you a PM to let you know where you can get the software from.
Thanks,
TE