Windows 7: Troubleshooting Device Problems (part 3)

Troubleshooting Device Driver Problems

Other than problems with the hardware itself, device drivers are the cause of most device woes. That is, if you open the device’s properties sheet, Windows 7 may tell you that the device is “working properly,” but all that means is that Windows 7 can establish a simple communications channel with the device. So if your device isn’t working right, but Windows 7 says otherwise, suspect a driver problem. Here are a few tips and pointers for correcting device driver problems:

• Reinstall the driver— A driver might be malfunctioning because one or more of its files have become corrupted. You can usually solve this by reinstalling the driver. Just in case a disk fault caused the corruption, you should check the partition where the driver is installed for errors before reinstalling.

• Upgrade to a signed driver— Unsigned drivers are accidents waiting for a place to happen in Windows 7, so you should upgrade to a signed driver, if possible. How can you tell whether an installed driver is unsigned? Open the device’s properties sheet, and display the Driver tab. Signed driver files display a name beside the Digital Signer label, whereas unsigned drivers display Not digitally signed instead.
  

• Disable an unsigned driver— If an unsigned driver is causing system instability and you can’t upgrade the driver, try disabling it. In the Driver tab of the device’s properties sheet, click Disable.

• Use the Signature Verification Tool— This program checks your entire system for unsigned drivers. To use it, select Start, type sigverif, and press Enter. In the File Signature Verification window, click Start. When the verification is complete, the program displays a list of the unsigned driver files (if any). The results for all the scanned files are written to the log file Sigverif.txt, which is copied to the %SystemRoot% folder when you close the window that shows the list of unsigned drivers. In the Status column of Sigverif.txt, look for files listed as Not Signed. If you find any, consider upgrading these drivers to signed versions.

• Try the manufacturer’s driver supplied with the device— If the device came with its own driver, try either updating the driver to the manufacturer’s or running the device’s setup program.

• Download the latest driver from the manufacturer— Device manufacturers often update drivers to fix bugs, add new features, and tweak performance. Go to the manufacturer’s website to see whether an updated driver is available. (See “Tips for Downloading Device Drivers,” next.)

• Try Windows Update— The Windows Update website often has updated drivers for downloading. Select Start, All Programs, Windows Update and let the site scan your system. Then click the Driver Updates link to see which drivers are available for your system.

• Roll back a driver— If the device stops working properly after you update the driver, try rolling it back to the old driver.

Tips for Downloading Device Drivers

Finding device drivers on the World Wide Web is an art in itself. I can’t tell you how much of my life I’ve wasted rooting around manufacturer websites trying to locate a device driver. Most hardware vendor sites seem to be optimized for sales rather than service, so although you can purchase, say, a new printer with just a mouse click or two, downloading a new driver for that printer can take a frustratingly long time. To help you avoid such frustration, here are some tips from my hard-won experience:

• If the manufacturer offers different sites for different locations (such as different countries), always use the company’s “home” site. Most mirror sites aren’t true mirrors, and (Murphy’s law still being in effect) it’s usually the driver you’re looking for that a mirror site is missing.

• The temptation when you first enter a site is to use the search feature to find what you want. This works only sporadically for drivers, and the site search engines almost always return marketing or sales material first.

• Instead of the search engine, look for an area of the site dedicated to driver downloads. The good sites will have links to areas called Downloads or Drivers, but it’s far more common to have to go through a Support or Customer Service area first.

• Don’t try to take any shortcuts to where you think the driver might be hiding. Trudge through each step the site provides. For example, it’s common to have to select an overall driver category, and then a device category, and then a line category, and then the specific model you have. This is tedious, but it almost always gets you where you want to go.

• If the site is particularly ornery, the preceding method might not lead you to your device. In that case, try the search engine. Note that device drivers seem to be particularly poorly indexed, so you might have to try lots of search text variations. One thing that usually works is searching for the exact filename. How can you possibly know that? A method that often works for me is to use Google (www.google.com) or Google Groups (groups.google.com) or some other web search engine to search for your driver. Chances are someone else has looked for your file and will have the filename (or, if you’re really lucky, a direct link to the driver on the manufacturer’s site).

• When you get to the device’s download page, be careful which file you choose. Make sure that it’s a Windows 7 driver, and make sure that you’re not downloading a utility program or some other nondriver file.

• When you finally get to download the file, be sure to save it to your computer rather than opening it. If you reformat your system or move the device to another computer, you’ll be glad you have a local copy of the driver so that you don’t have to wrestle with the whole download rigmarole all over again.

Troubleshooting Resource Conflicts

On modern computer systems that support the Advanced Configuration and Power Interface (ACPI), use PCI cards, and external Plug and Play–compliant devices, resource conflicts have become almost nonexistent. That’s because the ACPI is capable of managing the system’s resources to avoid conflicts. For example, if a system doesn’t have enough IRQ lines, ACPI will assign two or more devices to the same IRQ line and manage the devices so that they can share the line without conflicting with each other. (To see which devices share an IRQ line, activate Device Manager’s View, Resources by Connection command, and then double-click the Interrupt Request (IRQ) item.)

ACPI’s success at allocating and managing resources is such that Windows 7 doesn’t allow you to change a device’s resources, even if you’d want to do such a thing. If you open a device’s properties sheet and display the Resources tab, you’ll see that none of the settings can be changed.

If you use legacy devices in your system, however, conflicts could arise because Windows 7 is unable to manage the device’s resources properly. If that happens, Device Manager will let you know there’s a problem. To solve it, first display the Resources tab on the device’s properties sheet. The Resource Settings list shows you the resource type on the left and the resource setting on the right. If you suspect that the device has a resource conflict, check the Conflicting Device List box to see whether it lists any devices. If the list displays only No conflicts, the device’s resources aren’t conflicting with another device.

If there is a conflict, you need to change the appropriate resource. Some devices have multiple configurations, so one easy way to change resources is to select a different configuration. To try this, deactivate the Use Automatic Settings check box, and then use the Setting Based On drop-down list to select a different configuration. Otherwise, you need to play around with the resource settings by hand. Here are the steps to follow to change a resource setting: