After Upgrade to 12.1.SP2, if/when to delete old versions of PDMS? Where are MDB's?

Hi
I'm very new to PDMS, and have a couple of questions.
We have (2) users, each with their own desktop computer. Naturally, PDMS is installed on each desktop. The projects are stored on a server.
My questions:
1) After successfully installing the new version of PDMS, and upgrading the projects to 12.1.SP2, can I now delete the contents of the folders on the local computers that contain the previous version?
2) The real question is....Where are the MDB's stored? We have some of our own cats and specs that we created, I don't want to throw those out with the trash.

Thanks!

Ahh, got it figured out....can see the file locations using the database integrity check