Device Driver Basics

Most people understand that the "hardware" part of their computer is the real physical parts, like the keyboard, mouse, modem, hard drive and so on. They understand that the "software" is computer bits stored on the hard drive, CD-ROM, or other storage media. But most people are a little hazy about exactly what a "driver" is.
In this article, I'm going to reveal in plain English what a driver is, why we need drivers, and exactly where the drivers are hiding.




A hardware device is constructed with various electronic components using various control signals, but the software interface to the operating system is standardized. A device's interface to the operating system must follow the interface specification. A driver is a piece of software that translates the hardware's control signals to signals that the operating system expects, and translates signals from the operating system to the hardware's control signals.


When the computer is started up, it would look in the "system" directory for files with the extension ".drv" and load them into memory. Specific files like autoexec.bat, config.sys, and win.ini were used to inform the operating system about drivers. Hardware would be configured through these files, or through jumpers located on the device itself.

Driver Signing

Microsoft has been the brunt of much criticism because of the poor reliability of the Windows Operating System. The PC was designed by IBM as an "open" system. Anyone can sell a hardware device (or software) for the PC.

The operating system doesn't interface directly to a hardware device. There is a piece of software called a "driver" that translates the hardware's control signals to signals that the operating system expects, and translates signals from operating system to the hardware's control signals. Obviously, the hardware manufacturer provides the driver.

Because the driver works between the operating system and the hardware, a bug in the driver can cause a serious problem. Many of the problems with Windows have come from bugs in third-party drivers that Microsoft had nothing to do with. For this reason, Microsoft created a Hardware Quality Lab to test drivers. A hardware manufacturer can submit their driver for testing, and if it is passes rigorous compatibility testing, it receives Microsoft's digital signature.


You may have received a message during the installation of a hardware device warning that the driver was not signed. Why would a hardware manufacturer fail to have their driver certified by Microsoft? The computer hardware market is very competitive and the manufacturer might want to bring a new product to market before thorough testing can be completed. Or maybe they don't want to or can't afford to pay Microsoft for certification. The question is, should you click on the "Continue" button to install the unsigned driver?
In my experience, I have never been able to trace a problem to an unsigned driver. If it's your home computer and you performed a back-up recently, go ahead and install the unsigned driver. If it's a computer on a corporate network, you may want to back-out of the installation and see if you can locate a signed driver first.

To update a driver, select Start | Settings | Control Panel and double-click on the "System Properties" Utility. In the "System Properties" Utility, select the "Hardware" tab and click on the "Device Manager" button. In the "Device Manager" window, right-click on the device in the list and select "Properties" in the popup menu. In the "Properties" dialog box, select the driver tab and click on the "Update Driver..." button.

Post a Comment

Previous Post Next Post