How to Change / Set a default program in Windows 7
Instructions for changing the default program associated with a file type.
1) Open the Windows Start Menu by clicking on the Windows logo in the bottom, left-hand corner of the screen and select Default Programs.
2) Click on Associate a file type or protocol with a program.
3) Select the file type or extension you wish to associate with a program by default. For this example, we will set Adobe Acrobat as the default program to open PDF files. Then select Change Program.
4) Select the program you wish to set as the default and click Ok. If the program does not appear in the "Recommended Programs" list or the "Other Programs" list, you will need to click the Browse... button on the right-hand side of the window and manually locate the program.
The program and file type you selected should now be associated by default.