Associate a File Extension with a File Type
1. In Windows Explorer or My Computer, locate the file for which you want to create a file association.
2. Right-click the file, and then click Open With. If Open With is not an option, hold down the SHIFT key while right-clicking the file.
Open With should now be an option.
3. In the Open With dialog box, select the program that you want to use to open the file.
4. Click to select the Always use this program to open these files check box to make this the default program to open files with the same file-name extension.
5. Click OK.
The file now opens in the intended program.