说明：  Addfilter is a command-line application which adds and removes filter drivers for a given drive or volume. It is intended to demonstrate how to insert a filter driver into the driver stack of a device. The sample illustrates how to do this by using the SetupDi APIs. The sample works on the x86 platform. It has only been tested in a 32-bit environment. Since Addfilter is not a driver, it does not deal with Plug and Play or Power Management.