The sample drivers provide complete sources for creating many of the retail Windows 3.1 drivers. Using a sample driver as the starting point for your own driver can save you considerable time in incorporating the Windows 3.1 features.
If you decide to modify a sample driver, make sure you install all source files, tools, and related files from the DDK disks. If you change the organization of the sample files on your hard disk, be sure to make the appropriate changes to the make or batch file for building the driver.