In-depth analysis of Windows 7 device driver management

can provide good support for hardware, is a severe test for Windows 7, and is also an important indicator for users to choose Windows 7. The so-called hardware support, in the end is the device driver problem. What are the new features of Windows 7 in terms of hardware drivers? How to troubleshoot drivers in Windows 7? I think this is a user-related issue. I will combine my Windows 7 experience and my own understanding. For a more in-depth analysis of the device driver problem of Windows 7, I hope to help everyone.

1. Windows 7 device driver file interpretation

In Windows 7, a wide range of nearby driver libraries is included. In the basic installation of the operating system, these drivers are stored in the driver store, which is located in the %SystemRoot%System32DriverStoreFileRepository directory. In addition, a subfolder corresponding to the localized driver information is also saved in the DriverStore folder. For each language configured on the system, there is a corresponding subfolder here. For example, the author installed the English version of Windows 7, and the localized English driver information is located in the en-us subfolder. (Figure 1)

In the driver store, each device driver is certified and ensures full compatibility with Windows 7 systems, with Microsoft digital Signature, which ensures that the driver is absolutely available in the operating system. When installing a new compatible Plug and Play device, Windows 7 checks for available compatible device drivers in the driver store. If found, the operating system will automatically install the device.

Each device driver has an associated installation information file with an .inf extension that contains detailed configuration information about the device being installed. In addition, there are all source files to be used by each driver identified by the information file, which have a .sys extension. The driver is also associated with a component manifest file, which is written in an extensible markup language that contains detailed information about the driver's digital signature, and may also include a plug-and-play that configures itself to automatically use the device. information.

The source file for each driver installed on the Windows 7 system.sys will be saved in the %SystemRoot%System32Dirvers directory. When a new device driver is installed, the driver is written to a subfolder of %SystemRoot%System32Dirvers and configuration information is saved in the registry. The driver's .inf file can be used to control setup and setup information to be written to the registry. If the required driver is not saved in the driver store, or the .inf file is not used, or there is no other system file, in this case, the driver's .inf file and other related files are installed on the device. It will be written to a subfolder under %SystemRoot%System32DriverStoreFileRepository. (Figure 2)

2, Windows 7 device driver signature information should be valued

For Windows 7, can it provide good support for peripheral devices? Severe challenges. Without exception, in order to ensure the stability of the system and the good operation of the device, Microsoft recommends that the user choose to include the digital signature as the device driver version. This is very important for users, because Windows 7 is a new system platform after all, and all aspects need to be further tested or tested, which is generally ignored by many users. Device drivers with Microsoft digital signatures don't crash or become unstable, and Microsoft digital signatures ensure that device drivers have not been tampered with, which eliminates driver-level Trojans.

Conversely, if a user forces a driver that does not have a digital signature, it is likely to cause Windows 7 to become unresponsive or crash, which is even more serious than the problem caused by installing a normal program on the operating system. I have had such an experience. In addition, there are many cases in the forum that cause Windows 7 to crash due to the driver. Therefore, it is recommended for Windows 7 users to use signed drivers as much as possible. Of course, in some cases, we may find that the specific device is a driver that does not contain a signature. At this point, it is recommended that you search the device manufacturer for the website to see if a signed driver is available. Because sometimes there may be a driver with a signature, but it is not included in the driver CD of the device or the installation disk of Windows 7.

If no signed driver is available, only unsigned drivers can be used. In Windows 7, if you install an unsigned driver, be careful and closely monitor your system. If the system is found to be unresponsive or crashes, this may be caused by an unsigned driver, in which case you need to roll back the driver or uninstall the driver in question. At the same time, it should be noted that any type of device, even a graphics card, network card or sound card, may cause problems with the operating system if there is a problem with the corresponding driver. Sometimes, in order to prevent unsigned drivers from causing more serious problems, by default, Windows 7 issues a warning when we try to install an unsigned driver. Of course, we can also configure to cancel the warning or completely disable the installation of unsigned drivers. (Figure 3)

3, Windows 7 driver file troubleshooting

When the hardware driver installation error, not only can not drive the device, and it may cause The system is unstable or even crashes. The built-in hardware diagnostics of Windows 7 can detect various types of hardware device failures, so that the driver files can be debugged accordingly. Normally, if the system detects a problem, we will see a bubble notification for a problem report and a solution prompt. Click the bubble notification to open the problem report and solution console. Alternatively, we can open the console by clicking the System and Maintenance link in the Windows 7 Control Panel and clicking Problem Reports and Solutions. In the Problem Reports and Solutions window, click the View Issues to Check link to view an existing issue, or click the Check for Solutions link to search for possible solutions to known issues from the Microsoft website.

In addition, we can also directly debug the device driver by following the steps below: Open the device manager, select the "Device Manager" node, right-click the device to be debugged, select "Properties" On the General tab, click Check Solutions and click the View Details option to learn more about the issue. Of course, we can also send the question to Microsoft to find a solution, just click "send information". It should be noted that if the driver is not installed correctly, there will be no "check solution" option, but only the "reinstall device driver" option. In addition, when the device is installed incorrectly or has a problem, Device Manager displays a warning icon indicating a problem with the device. If you double-click on the device, the relevant error code will also be displayed in the General tab of the device's Properties dialog box. We can view the relevant reference documentation from the Microsoft website for troubleshooting. For example, error code 16, indicating that Windows does not recognize all the resources used by the device. The workaround is to check if the device has a signed driver available. If so, and already installed, you may need to manage the device's resources, which are set under the Resources tab of the device properties dialog. (Figure 4)

4, resource conflict caused by device driver troubleshooting

Sometimes, when we installed the driver file of a device in Windows 7, Will show resource conflicts, how to troubleshoot? The smart features of Windows 7 make it easy for us to troubleshoot this. If you suspect that a device is causing a resource conflict, you can quickly view the resources in the Device Manager of Windows 7 by clicking the View menu and selecting the Sort Resources by Type or Sort Resources by Connection view. Allocation, here we can see the use of IRQ by ISA and PCI devices. In general, each ISA device has its own IRQ settings, and multiple PCI devices share the same IRQ settings. The author specifically reminds that if some devices display a warning icon and an exclamation point, this is not a resource conflict, it should be a device configuration error. (Figure 5)

Another way to see if there is a resource conflict is to use the Windows 7 system information utility msinfo32.exe, click "Start" → "All Programs" ”→“Accessories”→“System Tools”→“System Information” to start the tool. In the system information window, expand “Hardware Resources”, then click “Conflict/Share” to list all the resources used. It should be noted that in Windows systems, devices can share IRQ settings, so two devices that are not related when sharing the same memory address or I/Q port often have conflicts between these devices. Once the two parties to the resource conflict are identified, we can manually modify the resource settings of some devices in Device Manager. Opening the device is a properties dialog, and in the Resources tab, select the type of resource you want to use. If you can change it, you can cancel the selection of "Use automatic settings" and then view the settings based on whether the candidate is available in the drop-down list. If there is a selection, the conflict can be resolved. (Figure 6)

5, Device Stage Technology That Has Been Say

Device Stage Technology is a new device solution added to Windows 7. It is mainly targeted at peripheral devices such as printers, camcorders, mobile phones, media players, etc. We can think of it as an enhanced version of Plug and Play technology. With Device Stage technology, users can easily set up and use a variety of peripherals. Click "Start" → "Devices and Prints" to enter the Windows 7 Device Management Center, which lists all the peripheral devices installed in the current system. As shown in the figure, it shows that the local system is equipped with a printer, a wireless headset, and so on. In this interface we can easily configure the corresponding hardware. It is worth mentioning that the icons of various devices are displayed in the Device Management Center of Windows 7. Sometimes when we install a device driver that is not developed for Windows 7, the system default icon may be displayed. If the driver is specifically developed for Windows 7, the icon for the device will be displayed, and Windows will be displayed. 7 The device stage technology will also read out the details of the device. (Figure 7)