When attempting to open a file that was saved from an attachment to an Outlook Express email message, the following message appears: ‘An error occurred when loading the file C:windowsprofiles…desktop…announcement. This file is not a valid Dr Watson file’. Who is Dr Watson and how can I stop him from trying to open my attachments?

You will be glad to know that Dr Watson is not a person, but is actually the debugger included in Windows to log system problems. As you can see, the general purpose of Dr Watson is not to open files, however it can be used to open log files. When you double-click the saved email attachment, it is attempting to open in Dr Watson. When Dr Watson sees the file is not a valid Dr Watson log file, it returns the error message.

The problem seems to be because the files you are saving have no file extension and Windows is attempting to open these files with Dr Watson. The file extension on the end of filenames (e.g. .DOC, .TXT) allows Windows to associate the file with a particular application. For example, Windows knows whenever there is a .DOC extension on the end of a file, that file should be opened with Microsoft Word. When there is no file extension on the end of the file, Windows does not know what application should be used to open the file and may exhibit strange behaviour (such as attempting to open the file in Dr Watson). Before starting any procedures, we should turn-on the display of file extensions for all files (otherwise things can get confusing, as you don’t know whether some files have extensions, or if some don’t). Go to the ‘Start’ menu > ‘Programs’ > ‘Windows Explorer’. Now, go to the ‘View’ (or ‘Tools’) menu > ‘Folder Options’. In the window that appears, click the ‘View’ tab. Untick ‘Hide file extensions for known file types’ and click OK. Now this is done, we have two options for correcting the problem. Firstly, if you know what the file extension for the file(s) should be, you can rename the file and type the file extension onto the end of the filename. For example, if the file ‘test’ is a Word document, this would be renamed as ‘text.doc’. By adding the file extension, Windows will be able to recognise the file as a particular type, and open that file type in the proper application. The second option is to open the application which should be used to view the file (e.g. Microsoft Word if the file is type .DOC) and then open the file from within the application.

However, should the file have the appropriate extension, but it still attempts to open using Dr Watson, we will need to reset the file extension so the files open in the correct application. Hold down the SHIFT key and right-click on the file. In the context menu that appears, click ‘Open with’¦’. A window will appear asking which application you would like to use to open that file type. Select the application from the list, or if the program is not listed, click the ‘Other’¦’ button to manually find the program. Once the application is selected, tick ‘Always use this program to open this type of file’ and click OK. Now, every time you open that file type it will open in the application you just defined. To change the program, simply repeat this procedure.