SAN FRANCISCO – Reader Marvin says that every time he double-clicks a Docx file (Docx is the default file format for Word 2007), it opens in Microsoft Works. How can he remedy this “extreme irritation”?

This fairly common problem is the result of an application–in this case Works–telling Windows that it is the default program for opening a certain file type, even though you didn’t ask it to. In other words, Works stole the file association for Docx files.

This commonly occurs with music files and photos as well. Fortunately, it’s pretty easy to restore a stolen file association. Here’s how:

1. Right-click any Docx file, mouse over Open with, and then choose Choose Default program. (Note: I’m describing Windows 7. If I recall my XP and Vista properly, you need to hold down the Shift key while right-clicking the icon, otherwise you won’t see the Open with option.)

2. You should see Word in the list of Recommended Programs. Click it, and then make sure there’s a check in the box marked Always use the selected program to open this kind of file.

3. Click OK and you’re done! The document will open in Word, and all subsequent Docx files you open should do likewise.

This same procedure will resolve just about any file-association issue you’re having–unless the file in question doesn’t open in any program. In that instance, check out Lincoln Spector’s Reassign a Lost Association.