How Windows Ranks Driver Packages

Note

This page describes how Windows determines a driver package rank value for a given driver package that matches on a device. To understand how driver package rank and other factors (including INF date, driver version, etc.) are used to determine which driver package Windows selects for a device, see How Windows Selects Drivers.

Windows assigns a rank to a driver package that matches a device. The rank indicates how well the driver package matches the device. A driver rank is represented by an integer that is equal to or greater than zero. The lower the rank, the better a match the driver package is for the device.

The rank of a driver package is a composite value that depends on a driver package's signature, the features that are supported by the driver package, and the type of match between the device identification strings that are reported by a device and the device identification strings that are specified in the entries of an INF Models section of a driver package INF file.

A rank is represented by a value of type DWORD. A rank is the sum of a signature score, a feature score, and an identifier score. A rank is formatted as 0xSSGGTHHH, where S, G, T, and H are four-bitfields and the SS, GG, and THHH fields represent the three ranking scores, as follows:

• The signature score ranks a driver package based on whether its digital signature is trusted. The signature score depends only on the value of the SS field. An unspecified signature score is represented as 0xSS0000000.

  For an overview on how Windows Vista and later versions of Windows use a driver package's signature to determine how the driver package is installed, see Signature Categories and Driver Installation.

• The feature score ranks a driver package based on the features that the driver package supports. The feature score depends only on the value of the GG field. An unspecified feature score is represented as 0x00GG0000.

• The identifier score ranks a driver package based on the type of match between a device identification string that is reported by a device and a device identification string that is listed in an entry of an INF Models section of a driver package INF file. The identifier score depends only on the value of the THHH field. An unspecified identifier score is represented as 0x0000THHH.

For information about entries in the SetupAPI log that indicate the rank of a driver package and the type of driver package signature, see Driver Rank Information in the SetupAPI Log.