did you also try to add the printer via the Application Settings -> Printers -> Add Printer?
If this does not work, please try the folloing: First restart your spooler to make sure it isn’t in use by a different application (run cmd.exe as admin and execute the commands net stop spooler and net start spooler. Now navigate to the PDFCreator folder and run printerhelper.exe /uninstall printer. Next run PrinterHelper.exe /InstallPrinter PDFCreator /PortApplication “C:\Program Files\PDFCreator\PDFCreator.exe” This will hopefully fix the problem, as it removes any PDFCreator printer related components (port, driver, printer) and creates them again afterwards, so there can’t be any conflicts with old drivers.