Whenever you install a new application to your Windows computer, it may set itself as the default program for certain file types and protocols. Many applications do this without your permission. For instance, your favorite media player may no longer open when you double-click on a video file, because something else has launched instead. It’s time to learn how to associate files in Windows with a default application.
First, the simplest method: right-click the file whose default application has changed, select Open with (and if a sub-menu appears, select Choose default program…). The computer displays a list of relevant applications that can open the file.
In Windows 8 or 8.1, check the Use this application for all .*** files checkbox before you choose an application in the list. If the application you want isn’t listed, select More Options. If you still can’t find your desired application, scroll down the list, select Look for another app on this PC, go to the application’s directory, select the app and click Open. You now have changed the default program for that file.
The list of apps looks slightly different in Windows 7, but the process is similar. The checkbox you need to mark is Always use the selected program to open this kind of file. If your application isn’t listed, click Browse, go to the application’s directory, select the app, and click Open.
If you want to view all programs that Windows uses by default, press Start, type Default Programs in the search field and select it when it appears in the results. Click Set your default programs if you want to find a program and select it as the default for all relevant file types. If you want to choose a default program for a specific file type, choose Associate a file type or protocol with a program instead.