Many times when we install programs, the install process will scan your computer for file types and then ask you if you would like these files to be open with the program being installed. Once the program is installed certain file types will be open with that program. For instance, if you install iTunes, the install will ask you if you want to open these music file types with iTunes. The file extensions can be mp3, wma, wav, etc. This short tutorial will show you how to change the file association with a particular program. In other words when you double click on a picture file you can designate which program opens the file.
Step1
Select: Start, Control Panel, Tools, Folder Options.Step2
In the folder option box select, File Types tab.Step3
Let’s use picture files as an example. Scroll down and locate jpeg which is one of the most common picture files used. All the file extensions are in alphabetical order so it makes it easy to quickly locate a file extension.Step4
Below the file extension window you will see “Opens with:” to change the program to open picture files, select the “Change” button. Select the new program that you want to use to open your jpeg picture files with.Step5
If your program is not found in the “Open with:” box then select, “Browse” button and then locate your program within the Program directory.Step6
Apply the exact same procedure for any other file types you wish to change your program association with. You can apply this method to movie files, sound files, pdf files, html files, etc. You can Google “File Types” to get a complete list of Microsoft file types and what they are used for. 
