Figure out why an application hangs

Find the source of mysterious program freeze-ups by searching the Web and running free diagnostic utilities.

Dennis O'Reilly Former CNET contributor
Dennis O'Reilly began writing about workplace technology as an editor for Ziff-Davis' Computer Select, back when CDs were new-fangled, and IBM's PC XT was wowing the crowds at Comdex. He spent more than seven years running PC World's award-winning Here's How section, beginning in 2000. O'Reilly has written about everything from web search to PC security to Microsoft Excel customizations. Along with designing, building, and managing several different web sites, Dennis created the Travel Reference Library, a database of travel guidebook reviews that was converted to the web in 1996 and operated through 2000.
Dennis O'Reilly
3 min read

Last December, it was Word 2007. Two weeks later, it was Outlook 2003. Out of the blue, a program that worked just fine yesterday freezes up today.

A few days ago, I described how to force Windows to close hung applications faster at shutdown. That fix might get you out the door quicker, but it doesn't address the source of the problem.

Unfortunately, determining the source of a hung application usually requires quite a bit of detective work. If the problem is widespread, chances are Microsoft and any other hardware or software vendors affected will do their best to make a fix available as quickly as possible--at least in the computer utopia that exists in my dreams. Most of these mystery freezes are uncommon and specific to a particular PC configuration, such as the driver for a certain model printer conflicting with a recent Windows security update, causing some functions in Windows Explorer to stop working (an instance described in a recent Microsoft knowledgebase article).

Step one: search the error code
When a program conks out, you usually see a window open with some error message, often including a code number. Enter the message and number in your favorite Web search engine and look for a link to an explanation, which may include a fix. This approach is more miss than hit, unfortunately. Gregory Braun's free Error Messages for Windows utility lists Windows error messages by their code numbers, but it doesn't help you find the source of the error.

Look up Windows error messages via the free Error Messages for Windows utility. Software Design--Gregory Braun

The usual suspects
The most obvious thing to check is for a malware infestation. Update your antivirus program's definitions and perform a full system scan. You're far from certain to discover any problems, but at least you can rule out a virus as the cause.

Often the problem is not the software's fault. Bad memory modules cause many programs to hang. Chris Brady's Memtest86 is a free program that diagnoses memory problems, though it requires that you copy its files to a floppy disk or disk partition, and then run the program from there. Microsoft's Windows Memory Diagnostic loads easier onto a floppy or CD from which you boot to run its tests automatically.

Another common crash culprit is an out-of-date video driver. To find your video-display make and model, right-click My Computer (XP) or Computer (Vista) and choose Manage > Device manager > Display adapters. Double-click the entry, choose the Driver tab, and note the driver version. Now visit the vendor's site and look for an update for the driver. (This also applies to drivers for other hardware devices.)

If your browser is crashing, disable your toolbar add-ons one at a time to determine whether one of them is causing the problem. You can disable add-ons in Internet Explorer 7 by clicking Tools > Manage Add-ons > Enable or disable add-ons, and then selecting them one at a time and choosing Disable. When you're done, click OK.

To disable add-ons and toolbars in Mozilla Firefox 2, click Tools > Add-ons, select the add-ons one at a time, and choose Disable.

Internet Explorer 7's Manage Add-ons dialog box
Find the cause of problems in Internet Explorer 7 by disabling add-ons and toolbars one at a time. Microsoft

Mozilla Firefox Add-ons dialog box
Determine whether an add-on or toolbar is the source of problems in Firefox by disabling them one at a time. Mozilla Foundation

To report or not to report
The Microsoft Online Crash Analysis site lets you upload your error reports and view an analysis of them, but it requires a Microsoft Passport account (Hotmail, Live, or MSN). You must also send your error reports to Microsoft whenever a crash occurs; most of us click Don't Send out of habit when the dialog box pops up. I had high hopes for this service, but after a recent crash of my XP system (caused by a bad program uninstall), it was no help whatsoever.

To disable error reporting in Windows XP, right-click My Computer, choose Properties > Advanced > Error Reporting, and click Disable error reporting. In Vista, press the Windows key, type Problem Reports and Solutions, and press Enter. Click Change settings in the left pane, choose Advanced settings, and click Change setting to the right of "For all users and programs, problem reporting is set to On." Choose Off, and close all the dialog boxes.

Tomorrow: Microsoft's one-stop shutdown-maintenance utility for XP.