Are you writing your own PostScript driver? Or are you trying to create an installer for a PostScript driver manufacturer? It is not clear what you mean by the PPD driver for Windows 7? Windows 7 comes with a perfectly fine PostScript driver that may be installed via .inf file with a .PPD file to create an instance for a particular driver on a particular port using the Add Printer Wizard.
If you do have questions about how the Windows PSCRIPT5.DLL driver works in conjunction with the PPD file, you need to get the Windows 7 DDK from Microsoft. Also, Microsoft officially supports that driver and how it interacts with PPD files, not Adobe.
- Dov