Association files

To control file associations, application developers can register a mapping between the file type and the handlers COM objects that provide functionality for the file type's Shell items.

When the Shell needs to query for the file associations of a file type, it creates an array of registry keys containing the associations for the file type, and checks these keys for the appropriate file associations to use. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Otherwise, register and sign in. Products 72 Special Topics 41 Video Hub Most Active Hubs Microsoft Teams.

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Enabling Remote Work. Small and Medium Business. Humans of IT. Green Tech. MVP Award Program. Video Hub Azure. Microsoft Business. Microsoft Enterprise. Select Folder Options near the bottom of the window. Open the File Types tab. Under Registered file types , scroll down until you find the file extension that you want to change the default program association for.

Choose the extension to highlight it. Select Change in the lower section. From the Open With screen that you're now looking at, choose the program you'd like to open the file type with by default. If you don't see that screen, choose Select the program from a list , and then OK.

The most common programs that support this particular file type will be listed under the Recommended Programs or Programs list, but there may be other programs that support the file as well, in which case you can manually select one with the Browse button.

You can also close any Control Panel or Appearance and Themes windows that might still be open. Going forward, any time you open a file with the extension you chose back on Step 6, the program you chose in Step 8 will be opened automatically and the file will be loaded within that program.

Changing a program's file association doesn't mean that another supporting program can't open the file, it just means that it won't be the program that opens when you double-tap or double-click on those types of files.

To use another program with the file, you'll just need to start that other program manually first , and then browse your computer for the particular file to open it. Also, changing the file association doesn't change the file type. To change the file type is to change the structure of the data so that it can be considered to exist in a different format. Actively scan device characteristics for identification.

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After you select "Choose another app," the following "How do you want to open this file? This window allows you to select a default program for the selected file type. Once you have selected a program, check the box next to "Always use this app to open. In the example above, clicking OK would set Paint as the default program for all files with a ". This method allows you to view and modify the full list of file associations available in Windows To access this list, open the Start menu click the Windows icon and select Settings.