A PPD is created each time you add a setup for a printer in PhotoPRINT / FlexiPRINT. You will need to share the PPD folder so that PPDs created from a printer setup on a Windows OS can be accessed from a Macintosh OS.
See Also
Preparing the Software to Receive Jobs from Clients
Sharing PPDs Over A Network for Windows Vista
Sharing PPDs Over A Network for Windows XP and 2003 Server
Setting Up File and Printer Sharing
Installing the AppleTalk Protocol
Windows Client Setup
Macintosh OS X Client Setup