When it comes to Windows, who is Dr. Watson?

You know all about Sherlock Holmes, but when it comes to Windows Dr. Watson is the man. Dr. Watson, named after the famous detective’s right-hand man, is a debugger application included with many versions of Microsoft Windows. Depending on the operating system version, it might be called drwatson.exe, drwtsn32.exe or dwwin.exe. After a problem has occurred, Dr. Watson collects the error information. In Windows Vista, Microsoft has replaced Dr. Watson with Problem Reports and Solutions.

The information collected by Dr. Watson can be used by a technical support team to diagnose the program error. At times, the file will only be of use to the developer, who can use it with the source code to figure out where the problem occurred. Whenever an error occurs, Dr. Watson creates a text file, which can be sent to the support team. This file will have a name such as Drwtsn32.log. Users can open the log file in a program such as Notepad and see which program caused the error.

A crash dump file will also be made. It is in binary form and support personnel will need to load it into a debugger to translate it. With the help of what are called “symbol files,” Dr. Watson can create detailed reports for debugging.

In Windows, when a program error happens, the operating system looks for an error handler. If an error handler is not found, Windows considers the problem to be unhandled. It then proceeds to look in the Windows registry for a program, error debugger. Dr. Watson is the default debugger. Some users opt to use a third-party debugging program, such as the crash analysis tool Dr. Watcom.

The errors logged by Dr. Watson are generated by the Central Processing Unit (CPU) and signaled to the operating system. They usually can be categorized as:

1. An attempt to access data or code without having sufficient privileges
2. Trying to access invalid code or data
3. The CPU attempting to access illegal instructions