14. The computer-readable storage medium according to claim 10 , wherein the preview screen is displayed by validating a preview setting in a setting screen of a printer driver that can receive a document of an XML Paper Specification format (XPS format) and process the document of an XPS format, and a combined document is generated.
10. A computer-readable storage medium storing computer-executable instructions that cause a computer to execute a method comprising: displaying a preview screen; and selecting a storing function in accordance with an instruction input in the preview screen, wherein information of document data and a preview image of the document data are displayed in the preview screen, wherein if the storing function is selected, the information of the document data is displayed in the preview screen after printing for the document data, and if the storing function is not selected, the information of the document data is not displayed in the preview screen after printing for the document data, and wherein if first information of first document data for which print processing has already been performed or second information of second document data for which print processing is to be newly performed is selected in accordance with an instruction input via the preview screen and print setting information is changed, print setting information of document data corresponding to the selected information is changed and print setting information of document data corresponding to information not selected is not changed.