The methods you use to change file associations—that, which apps or applications are used to open specific file types—in Windows 8 are similar to how things work in Windows 7. But there a few major changes: Some of the interfaces you use now are Metro experiences. And in Windows 8, you get to choose between Metro style apps and desktop applications.
A stock install of Windows 8 will include some interesting new file associations. The new Windows Reader app, for example, is configured to open PDF, XPS, and OXPS files by default. The Photos app is configured to open a wide range of picture files. Xbox Video is configured to play all video files, and Xbox Music is configured for audio files. Internet Explorer 10 is preconfigured to open web pages. And so on.
You may not want things configured this way. Desktop users, for example, will most likely want to install desktop applications—like Adobe Reader for PDF files, Windows Photo Gallery for pictures, and perhaps VLC Media Player for videos—that make more sense for their needs. But whatever the reason, you can change Windows 8 file associations easily enough.
There are two basic methods.
The first occurs automatically when you’ve installed a new (Metro) app or (desktop) application that registers its ability to open certain file types with the system. For example, VLC Media Player is compatible with a variety of video file types. But when your try to open a video file after installing this application, it will still open in the previously associated app/application, which is Xbox Video by default.
But because you’ve installed another app or application that can handle this file type, Windows 8 will display a Metro-style notification alerting you that there are other solutions that can open files of this type. If you click this notification, you’ll be given the new Metro-style interface for making an on-the-fly file association.
You don’t have to handle this immediately, however. As with Windows 7, you can make file association changes at any time using the Default Programs interface, which remains a classic control panel, and not a new Metro experience. (As always, the easiest way to find this interface is Start Search: Search for default and then choose Default Programs.)
From this interface, select Set your default programs and then locate the app or application you wish to use with certain files types from the list.
Then, you can select Set the program as default—to use this app or application for all possible associated file types—or click Choose defaults for this program to see a list of the possible file types you can associate.
Windows will make the change. And now, when you open these file types from File Explorer or elsewhere in Windows, the application (or app) you want will always be chosen by default.