Developer

Set up Dr. Watson for quality system debugging

Sherlock Holmes always used his faithful assistant Dr. Watson when it came to solving crime. With a little preliminary setup and configuration, you, too, can use Dr. Watson to solve some of the mysteries often associated with system crashes.


Most applications installed on your client's Windows XP workstations and laptops contain all the code necessary to handle or recover from errors. However, we've all experienced occasions where an application simply locks up the system and gives us no good reason why it's malfunctioning. These unhandled errors must be addressed by the system in some way. For Windows XP, unhandled errors are handled within the registry located at the following key:
\HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AeDebug

It is here that our old friend Dr. Watson usually makes an appearance. The debugging tool has been around for years, yet it has been the source of much confusion when it comes to trying to decipher its findings. However, following these steps can help you get a better idea of what is going on with your client's machine.

Note
If your client has another debugger on its system, and you feel Dr. Watson is a better choice, you will need to perform a registry change to make the switch. Simply go to Start | Run and enter cmd to obtain a command prompt. At the prompt, type the command drwtsn32 -i to start Dr. Watson. Typing -i causes the necessary changes to be made within the registry.

Capture more information with symbols
As mentioned before, Dr. Watson's debugging output can be cryptic even to a seasoned IT pro. Debug symbols allow you to capture more targeted information. Unfortunately, obtaining and installing these symbols on a machine before an error occurs does not often happen. Being proactive, however, is not as difficult as it used to be. The obtaining part of the equation is accomplished by simply downloading these symbols from Microsoft's Web site. The installation process is a little more involved.

You begin by creating a system root subfolder on the computer and naming it something like "Symbols." Copy the symbols you downloaded to the new subfolder. Next, you need to right-click My Computer, select Properties, and navigate to the Advanced tab. At the bottom of the tab, click on the Environment Variables button to display the dialog box shown in Figure A.

Figure A


Select the New button in the System Variables list (the second list in the dialog box), and give your symbols the variable name _NT_SYMBOL_PATH. In the Variable Value text box, enter the path to the root subfolder you created earlier for the symbols. Now, your client's system should provide more valuable debugging information when an error occurs.

Tweaking Dr. Watson
A final tip to working with the Dr. Watson debugging tool is to adjust some of the settings within the program. One way to access these settings is to click on Start | All Programs | Accessories | System Tools | System Information, and then select the Dr. Watson program from the Tools menu. You'll now see the Dr. Watson dialog box shown in Figure B.

Figure B
For a shortcut to the Dr. Watson tool, simply click on Start | Run and enter drwtsn32.exe.


From this dialog box, you can tweak several options. For an explanation of each setting, click on the Help button and select the Working With Dr. Watson link.

Editor's Picks

Free Newsletters, In your Inbox