How to Found all Disk on Key drivers

Hi

I have a database that contain a filename (of file).

I want to add an option to the user to copy the file from the database for desktop or any disk on key that plug in the computer.

So I want to add to my pop-up menu a Copy sub-menu that will contain Desktop and all Disk on key drives (For example: Desktop, E:\, F:\, etc.)

So I have two questions:

1. How can I know all DoK drivers ?

2. Can I update the popup menu during runtime (I mean: Can I update the popup menu with new Disk on Key drives when the menu is open..)

Thank you !