WDM Driver Installation Process

A WDM driver is installed if a new device is detected by a bus driver, or if you install a device using the Add New Hardware wizard in the Control Panel. A later section describes how the right driver is found. In both cases, the Plug and Play (PnP) Manager adds entries for the device and its driver to its configuration tables in the registry.

A driver is installed by following the instructions in an INF file. The driver executable is copied to the right location, usually the Windows System32\Drivers directory. Then various registry entries have to be made.

Some devices may now need to have some system resources assigned to them, such as I/O Port addresses and interrupt numbers. The PnP Manager may need to juggle the resources that have been assigned to existing devices to make the desired resources available to the new device. If necessary, existing devices are stopped (if they agree) and their resources reassigned.

If the driver is not already present, it is loaded and its DriverEntry routine is called. The driver AddDevice routine is called for the new device. Various Plug and Play IRPs are then sent to the device as detailed in...