Dear,
In order to make the PDF file plese install Adobe Acrobat distiller in your machine. Once you install the Distiller then activate QuarkXPress. Go to the Preferences. In PDF preference, browse the Acrobat Distiller by clicking the browse button.
To find out where the AcroDist.exe is - try finding it from the Windows Search option.
Once you browse the specified the AcroDist.exe, try making the PDF.
Hope this help,
Please revert back to me if further assistance is required.
Regards,
TechLeo