enum INSTALLLOGATTRIBUTES // flag attributes for MsiEnableLog

        enum INSTALLLOGMODE  // bit flags for use with MsiEnableLog and MsiSetExternalUI

public static extern UInt32 MsiEnableLog(INSTALLLOGMODE dwLogMode, string szLogFile, INSTALLLOGATTRIBUTES dwLogAttributes);

        public enum INSTALLLOGMODE  // bit flags for use with MsiEnableLog and MsiSetExternalUI

        public enum INSTALLLOGATTRIBUTES // flag attributes for MsiEnableLog

MsiEnableLog(INSTALLLOGMODE.INSTALLLOGMODE_VERBOSE, logFileFullPath,

You can set the log mode by using the MsiEnableLog function.

    MsiEnableLog(INSTALLLOGMODE.INSTALLLOGMODE_VERBOSE, "C:\\temp\\log.log", INSTALLLOGATTRIBUTES.INSTALLLOGATTRIBUTES_APPEND);