Associate a File Type with a Specific Program

We Are going now to access the Set Associations window :

•  Click the Start button.
•  Select Control Panel.
•  Select Programs.
•  Under Default Programs, select Make a file type always open in a specific program.
  When the set associations Program will appear , you will be able to change what program a file type is associated with.

So you Select the file type and clicking the Change program button.
*to change only single file type :
Right-click on a file and select Properties. Under the General tab, click the Change button then select the desired program.