Blue Screen of Death

Why your computer still crashes.

There’s nothing like an untimely computer crash to ruin your day—or at least ruin your reputation for keeping cool on a deadline. Crashes can range from moderately frustrating application shutdowns and “not responding” pop-ups to the fearsome Blue Screen of Death, which brings your entire PC to a complete halt. Even my supposedly robust Mac isn’t immune to this sort of fatal system failure. My machine has seized up at least once a week for the past two years, covering the screen with a transparent panel that says “You need to restart your computer” in four languages.

So, why does your computer go on the fritz? More important, is there any way you can stop it from happening?

If one application is always shutting down, you’re probably in luck. If you have a PC, search Microsoft’s knowledge base for articles about “illegal operation” problems associated with the application. For a Mac, go to Apple’s support page and search for “unexpectedly quits.” If that fails, type the error messages you see into Google (e.g. “The application Microsoft Word has unexpectedly quit”) to find message board posts about the problem.

The death screen isn’t as easy to figure out. In fact, there’s often no way for anyone except a technician packing professional-grade diagnostic tools to find the culprit. A bug in one program can corrupt data in the computer’s memory, causing an entirely different program to crash later. Bad hardware will also often lead to software errors; when the hardware doesn’t send back data as expected, programs will start to fail. “A broad range of conditions can cause a Fatal Exception error,” shrugs Microsoft’s help documentation. “As a result, troubleshooting a Fatal Exception error can be difficult.”

You probably won’t be able to figure out what’s wrong with your computer by reading the gibberish on the Blue Screen of Death, but you can make an educated guess. A few years ago, Microsoft set up the Windows Error Reporting Service to help find out where crashes come from. After a Windows application—or your whole PC—shuts down, a box pops up asking you to send a confidential error report. Using pattern-matching software to sift through the data from millions of these reports, Microsoft discovered a surprising statistic. Seventy percent of Windows crashes involve one particular kind of software: device drivers. (I couldn’t get stats for the Mac, but, at least anecdotally, device drivers are a major cause of drop-dead crashes.)

Device drivers handle communication between the PC’s core operating system (the kernel) and hardware devices like the hard disk and the printer. When you send a file to be printed, for instance, a device driver custom-coded for your specific model asks the printer if it’s good to go and translates any responses—such as an out-of-paper alert—into a format that Windows understands. (Click here for a more technical explanation of how drivers work.) Because device drivers tie hardware and software together, they have special privileges that your browser and word processor don’t. If a device driver gets an error message it’s not sure how to deal with, it can call a “bug check”—the big blue screen—as a way to halt everything before your data gets scrambled. Conversely, the Windows kernel can pull the trigger if a device driver’s not responding properly.

But luckily, if you’ve got a device driver problem, there are probably lots of other people whose computers are crashing due to the same error. In fact, the hardware manufacturer might have published an improved version of the driver that can fix the problem.

If your PC is outfitted with a brand-name printer, scanner, or CD burner, its device drivers will likely have passed the exhaustive (and expensive) tests that allow bug fixes to be distributed via Windows Update. Go to the Windows Update site, click on Custom Install, and look at the optional hardware updates on the left side of the screen—that’s where you’ll typically find updated device drivers. Unfortunately, even if you’ve set Windows Update to run automatically, you’ll still have to go get new drivers manually. If you’ve got a Mac, Apple’s Software Update service automatically installs updated drivers for Apple hardware on computers running OS X.

If you’ve got a PC with hardware that doesn’t meet the Windows gold standard or a Mac with a peripheral that’s not made by Apple, you’ll have to do some hunting. As a case study, I have a 5-year-old PC that crashed midsong every time I tried to play MP3s with RealPlayer. After years of fuming about Real’s buggy software, I finally realized I might be having a device driver problem. What could be prone to glitching when playing music—maybe the sound card? Come to think of it, I hadn’t seen an update for the card’s device driver in two years of using Windows Update. I went to My Computer, then System Properties, and then found the model of the card by clicking on the Hardware tab. After Googling for the brand name and “driver,” I found a free, updated device driver on the manufacturer’s Web site. Sure enough, problem solved.

The same approach solved my Mac crashes. My add-on Wi-Fi card doesn’t use Apple’s built-in device drivers; instead, I had downloaded a free one written by a generous programmer. Since this freeware driver hadn’t been exhaustively tested by a big corporate lab, it wasn’t shocking that it occasionally acted buggy. By searching message boards, I found a different driver that hasn’t invoked the crash screen yet. (If you’re looking for drivers for non-Apple hardware or older versions of the Mac OS, always try the Apple Discussions site before roaming the Web.)

I got a little lucky in both these cases, but the odds were on my side. Likewise, if your computer is crashing regularly, you won’t do any harm by looking for new device drivers. (One exception: Don’t mess with video drivers unless you know what you’re doing—you could end up with an unusable computer.) Always be sure to save a copy of your current driver before installing a new one (click here for instructions). If your new driver causes more problems than it cures, Windows XP has a Control Panel option to roll back to the previous version, or you can swap it back manually on older versions of Windows. You can always just cross your fingers, search the Web, and try again.

Webhead thanks Gabriel Aul, group program manager of Microsoft’s Feedback and Supportability Platform Team, and Anuj Nayar, Mac OS X PR manager for Apple.