Not every device requires its own INF file. Many devices that use the system’s class drivers can use the INF file that Windows provides for the class. These are some INF files for USB classes included with Windows XP.Because Windows XP and later prefer signed drivers, if you provide an unsigned driver for a device in a supported class, Windows XP and later won’t
use your driver and instead will select a compatible ID from the class’s INF file.

An INF file is considered part of the driver package, so Windows XP and later prefer a system-provided INF file for a system driver over an unsigned, vendor provided INF file for the same driver even if the vendor’s INF file contains a matching hardware ID. When the best match is an unsigned driver, operating-system settings can affect whether Windows blocks installation, installs the driver with a warning, or installs with no warning. To change the setting, in Windows Control Panel, select System > Hardware > Driver Signing.

A device that uses a class driver can have a custom, signed INF file with vendor specific strings that display in the Device Manager. For example, the entry for a HID can be a vendor-specific string instead of the default USB Human Interface Device. Many INF files provided with Windows contain sections with manufacturer specific information. When a device passes WHQL tests, Microsoft can add the device’s sections to an existing INF file or add a manufacturer-specific INF file to the files distributed with Windows.