Dr. Watson overview
Dr. Watson for Windows is a program error debugger.

The information obtained and logged by Dr. Watson is the information needed by technical support groups to diagnose a program error for a computer running Windows. A text file (Drwtsn32.log) is created whenever an error is detected, and can be delivered to support personnel by the method they prefer. You also have the option of creating a crash dump file, which is a binary file that a programmer can load into a debugger.

If a program error occurs, Dr. Watson will start automatically. To start Dr. Watson, click Start, click Run, and then type drwtsn32. To start Dr. Watson from a command prompt, change to the root directory, and then type drwtsn32.


Setting up Dr. WatsonDr.
 Watson (Drwtsn32.exe) is installed in your system folder when you set up Windows. The default options are set the first time Dr. Watson runs, which can be either when a program error occurs or when you start Dr. Watson yourself.

When a program error occurs in Windows, the system searches for a program error handler. A program error handler deals with errors as they arise during the running of a program. If the system does not find a program error handler, the system verifies that the program is not currently being debugged and considers the error to be unhandled. The system then processes unhandled errors by looking in Registry Editor for a program error debugger.

The system looks in Registry Editor under the key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AeDebug for the entries named Debugger and Auto. The value for the Debugger entry specifies the command for the debugger that will be used to analyze program errors. If the value for the Debugger entry is found, the system checks to see if the value for the Auto entry is set to zero or one.

If the value for the Auto entry is set to zero, the system generates a message box that notifies you that a program error has occurred. If the value for the Debugger entry specifies the command for a valid debugger, the message box will display two buttons: OK and Cancel. If you click OK, the program is terminated. If you click Cancel, the specified debugger is started. If the value for the Debugger entry is empty, the message box will display only OK, and no debugger will start.
If the value for the Auto entry is set to one and the value for the Debugger entry specifies the command for a valid debugger, the system automatically starts the debugger and does not generate a message box.
When Windows is set up on your system, the value for the Auto entry is set by default to one and the value for the Debugger entry specifies the command to start Dr. Watson. This means that when a program error occurs, Dr. Watson for Windows will automatically diagnose the error and log the appropriate diagnostic information.

If you have been using a program other than Dr. Watson as your default debugger, and you want to use Dr. Watson instead, go to the command prompt and type the command drwtsn32 -i to start Dr. Watson. Typing -i causes the necessary changes to be made to the registry.

Dr. Watson can be made to generate more exacting information for debugging purposes if the appropriate symbols are installed and the symbol search path is set. To do this, you first need to copy the symbols from the Windows CD-ROM into a new folder on your computer. Then you need to create a new system environment variable. First, go to the systemroot folder on your computer and create a new folder named Symbols. Next, go to the CD under \\Support\Debug\i386 and copy the symbols to the Symbols folder that you created on your computer. After the symbols have been copied, create a new system environment variable. While creating the new system environment variable, type _NT_SYMBOL_PATH for the variable name and %systemroot%\Symbol for the variable value. You can install various symbols to different locations separated by semicolons and point to each of those locations using the same environment variable. Be sure to include variables for added service packs. For example: _NT_SYMBOL_PATH=%systemroot%\symbol;%systemroot%\hotfixes;%systemroot%\symbolsNt4Sp3.

Dr. Watson is a program that:

1. Detects application errors.
2. Starts automatically if an application error occurs.
3. Logs the diagnostic information by creating a drwtsn32.logfile, which is an electronic text file.

In an ICM environment, the drwtsn32.log file is located in the c:\winnt directory.

The drwtsn32.log file is appended each time a program error occurs. If there is an existing drwtsn32.log file, and a new error occurs, the new information will be added to the existing file. If there is no drwtsn32.log file, a new one will be generated.  For this reason, after providing a drwtsn32.log file to the appropriate people, delete the file. In the event that a new error occurs, a new drwtsn32.log file will be generated.

Using the findstr command against the drwtsn32.log file can help in pin pointing applicable information for diagnosing the problem and for log file gathering.

From a command prompt, use the findstr command to search the drwtsn32.log file for:

• When
• App
• FAULT

• The date and time the problem occurred
• Which application/process caused the problem
• What the actual fault is.