For each hardware component installed on a computer, there is an associated device driver.
The job of the device driver is to describe how the operating system
uses the hardware abstraction layer (HAL) to work with a hardware
component. The HAL handles the low-level communications tasks between
the operating system and a hardware component. By installing a hardware
component through the operating system, you are telling the operating
system about the device driver it uses, and from then on, the device
driver loads automatically and runs as part of the operating system.
Windows 8 includes an extensive library of device drivers. In the
base installation of the operating system, these drivers are maintained
in the file repository of the driver store. Some service packs you
install will include updates to the driver store. On 32-bit computers,
you’ll find the 32-bit driver store in the %SystemRoot%\System32\DriverStore
folder. On 64-bit computers, you’ll find the 64-bit driver store in the
%SystemRoot%\System32\DriverStore folder and the 32-bit driver store in
the %SystemRoot%\SysWOW64\DriverStore folder. The DriverStore folder
also contains subfolders for localized driver information. You’ll find
a subfolder for each language component configured on the system. For
example, for localized U.S. English driver information, you’ll find a
subfolder called en-US.
Every device driver in the driver store is certified to be fully
compatible with Windows 8 and is digitally signed by Microsoft to
assure the operating system of its authenticity. When you install a new
Plug and Play–compatible device, Windows 8 checks the driver store for
a compatible device driver. If one is found, the operating system
automatically installs the device.
Every device driver has an associated Setup
Information file. This file ends with the .inf extension and is a text
file containing detailed configuration information about the device
being installed. The information file identifies any source files used
by the driver as well. Source files have the .sys extension. You might
also find .pnf and .dll files for drivers, and some drivers have
associated component manifest (.amx) files. The manifest file is
written in XML, includes details about the driver’s digital signature,
and might also include Plug and Play information used by the device to
automatically configure itself.
Every driver installed on a system has a source (.sys) file in the Drivers folder. When you install a new device driver, the driver is written to a subfolder of the Drivers
folder, and configuration settings are stored in the registry. The
driver’s .inf file is used to control the installation and write the
registry settings. If the driver doesn’t already exist in the driver
store, it does not already have an .inf file or other related files on
the system. In this case, the driver’s .inf file and other related
files are written to a subfolder of DriverStore\FileRepository when you
install the device.
Using Signed and Unsigned Device Drivers
Every device driver in the driver cache is digitally signed, which
indicates that the driver has passed extensive testing by the Windows
Hardware Quality Lab. A device driver with a digital signature from
Microsoft should not cause your system to crash or become unstable. The
presence of a digital signature from Microsoft also ensures that the
device driver hasn’t been tampered with. If a device driver doesn’t
have a digital signature from Microsoft, it hasn’t been approved for
use through testing, or its files might have been modified from the
original installation by another program. This means that unsigned
drivers are much more likely than any other program you’ve installed to
cause the operating system to freeze or the computer to crash.
To prevent problems with unsigned drivers, Windows 8 warns you by
default when you try to install an unsigned device driver. Windows can
also be configured to prevent installation of certain types of devices.
To manage device driver settings for computers throughout an
organization, you can use Group Policy. When you do this, Group Policy
specifies whether and how devices can be installed.
You can configure device installation settings on a per-computer
basis using the Administrative Templates policies for Computer
Configuration under System\Device Installation.
Tip
If you’re trying to install a device and find that you can’t, device
installation restrictions may be in place in Group Policy. You must
override Group Policy to install the device.
Tracking Driver Information
Each driver being used on a system has a driver file associated with
it. You can view the location of the driver file and related details by
completing the following steps:
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Start Computer Management. In the Computer Management console, expand the System Tools node.
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Select Device Manager. You should now see a complete list of devices
installed on the system. By default, this list is organized by device
type.
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Press and hold or right-click the device you want to manage, and
then tap or click Properties. The Properties dialog box for that device
opens.
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On the Driver tab, tap or click Driver Details to display the Driver File Details dialog box. As shown in Figure 1, the following information is displayed:
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Driver Files
Displays the full file paths to locations where the driver files exist
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Provider The creator of the driver
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File Version
The version of the file
