Driver Install Frameworks API (DIFxAPI) version 2.1 is a component of Driver Install Frameworks (DIFx) version 2.1. DIFxAPI simplifies the creation of applications that install and uninstall driver packages and is available starting with Microsoft Windows 2000. DIFxAPI includes the following components:

• 32-bit components that support x86-based systems.
• .
• 64-bit components that support x64-based systems.
• 64-bit component that support Itanium-based systems.

For new installation applications, use DIFxAPI version 2.1 instead of DIFxAPI version 2.0, which did not fully support Windows Vista and later versions of Windows.

Starting with Windows 7, the Windows Driver Kit (WDK) includes version 2.1 of DIFxAPI. For information about how to obtain the latest WDK, see How to Get the WDK.

Note  Although version 2.1 of DIFxAPI was available in earlier versions of the WDK, use the version of DIFxAPI in the Windows 7 WDK and later versions of the WDK. With this version of DIFxAPI, you get compatibility with previous and future versions of Windows.

DIFxAPI simplifies the following:

• Preinstalling Plug and Play (PnP) driver packages in the DIFx driver store with a single DIFxAPI function call. After a driver package is preinstalled, Setup will automatically install the driver for a device that is subsequently connected to a computer, if the driver is the best match for the device.
• Installing a driver package with a single DIFxAPI function call and uninstalling the driver package with a single DIFxAPI function call. DIFxAPI supports driver packages that comply with the DIFx driver package requirements.

• Associating a driver package with an application when a driver package is installed and removing the association when the driver package is uninstalled.
• Retrieving and using the path of a DIFx driver store INF file of a preinstalled driver package. The path of a DIFx driver store INF file identifies a driver package that was preinstalled in the DIFx driver store. An installation application can use this INF file path to uninstall a driver package from the DIFx driver store.
• Logging significant events to an application that occur during the preinstall, install, or uninstall of a driver package. For more information about event logging, see Using DIFxAPI Event Logging.

For information about how to link an installation application to DIFxAPI, see Linking an Installation Application to DIFxAPI.