A short explanation about profiles in the PDF-XChange Standard Driver.
Profiles represent a collection of printer settings. Currently they include all possible settings from the “Printing Preferences” pages of the driver, except the list of custom forms. Custom forms are kept outside of profiles, however this may cause what can appear as inconsistencies in usage.
The default profile is stored under HKEY_LOCAL_MACHINE and is treated as read-only, users cannot overwrite it. For users, profiles are stored in the registry under HKEY_CURRENT_USER.
Every printer in Windows stores its settings in the registry in the structure called DEVMODE. That structure has a part common for all printers, where settings like paper size, dpi, orientation, etc. are stored. It may contain additional data known as PRIVATEDEVMODE. The structure of PRIVATEDEVMODE is designed by individual printer developers and typically is not published.
Currently, the PDF-XChange driver stores all settings, except the list of custom forms, in its DEVMODE.
How it works
DEVMODE and Profiles working together.
Selecting a profile from the list of profiles copies all settings from that profile to the DEVMODE; the printer takes the name of chosen profile for display in the UI (User Interface). Selecting the ‘fake’ profile “Default Profile” causes all settings to be reset to their default built-in values.
Any change to the printer’s settings modifies DEVMODE but not the original Profile. The profile remains unmodified. That is the most important change that was introduced in build 308. Any changes can be stored back to the profile by using the “Save” button in the printer preferences dialog. If the original “Default Settings” profile is loaded when changes are made it cannot be saved (the “Default Settings” profile is read only), this button will be disabled and saving the changes must be done using the “Save As” button thus creating a new named profile with the current settings.
Profiles are not modified until a user explicitly saves current settings to an existing or new profile.
Switching between profiles abandons all current settings as these settings are replaced with ones from the chosen profile.
Custom forms reside outside of profiles for now. Custom forms are common for all profiles.
Read Only Vs User Editable profiles
Profiles stored under HKEY_CURRENT_USER are user defined and can be modified by users. This is the default for profiles created using the GUI.
Profiles stored under HKEY_LOCAL_MACHINE are treated as read-only and users cannot overwrite them. User cannot save profiles to HKLM through the GUI, it must be done through the command line as a user with appropriate privileges.
To make a profile Read Only and available to all users see here: KB#498