How to Change a File Association
You may want to change the association of a file name extension from one program to another program. To change an existing file association:
1. In My Computer or Windows Explorer, right-click a file with the extension whose association that you want to change, and then click Open With.
2. In the Open With dialog box, click the program that you want to use to open the file type. Or, click Choose Program to choose the program that you want. If the program is not listed, click Other to locate your program.
3. Click the Always use the selected program to open this kind of file option.