Change the default program to open a file in Windows

When a file on a Windows PC is double clicked in Explorer or on the desktop, which program opens it? The wrong one? Set the default apps for any file type so they open in the one you want.

When you double click an audio file, which program opens and plays it? When you double click a .jpg photo, which program is used to display it or edit it? Does double clicking a .png file open in the same program? What about PDFs? Does the right program always open or would you prefer another one was used? You can easily choose.

Whenever a file is double clicked, Windows looks at the file type, which is the letters after the dot in the filename, such as .jpg, and loads whatever program is associated with it. So double clicking a .docx file will open Microsoft Word, providing you have it installed, and double clicking a .txt file will open it in Notepad.

How do you get another program to open a particular file type?

1 Default apps in Windows 10 Settings

Open the Settings app in Windows 10 from the Start menu or by pressing Windows+I. Click Apps and then select Default apps in the sidebar. A list of default apps is displayed. These are like categories of file rather than specific file types, so there is Music Player, but which audio file types does it play? It is not clear.

Some categories of app may have the wrong app associated with it or there may be none set. There is no photo viewer in the screenshot above.

2 Set a default app

Whether you want to change a default app or set one where there isn’t one, click the icon or plus button. A list of apps is displayed and the items on the list depend on what software you have installed. In the screenshot, the Photo viewer default is set to the Photos app, but any on the list can be selected.

Unfortunately, there is no option to browse the disk and select any app you want. You can only select from the list. However, if you scroll right down to the bottom, there is an option to search the Windows Store for a suitable app. It is not ideal, but we are stuck with this small list.

3 Set default apps by type

Scroll to the bottom of this section of Settings and there is a Reset button which sets all file associations to the ones Microsoft recommends. This is rarely needed.

Click Choose default applications by file type.

4 Associate a program with a file type

A couple of steps back, the default for Photo viewer was set to the Photos app. There are dozens of photo file types, such as .jpg, .png, .gif, .tif, .bmp and many more. Is it just .jpg, all types or just some of the types?

Here you can choose which app is opened when a particular file type is double clicked. To change the program associated with a file type, click it and choose a new program from the list displayed.

This enables you to open any file type in any app you choose. One type of image file could open in one app and another type of image file could open in a different app. If you just installed software which changed the program associated with a file type, change it back here.

5 Set default apps for a protocol

Back in step 4, click Choose default applications by protocol. What is a protocol? This is not a file, but a link to a website, an email link and similar things. For example, a shortcut to a website could be saved to the Windows desktop and double clicking it will open a web browser to show the website. Which browser? The default one, the one associated with the HTTP or HTTPS protocol.

Here you can change the default web browser, email client, and similar things. Click an item and choose the program you prefer to use. It has to be one on the list and you cannot browse the disk for a program.

Set program defaults in Windows 7/8

Open the Control Panel, select Small icons in the View by list if necessary, and then click Default Programs. Click Set your default programs. (Do this in Windows 10 and you get bounced back into the Settings app.)

There is a list of programs on the left hand side. Suppose we want to change the programs that open in Paint. Select it on the left and on the right is says that the program has 3 out of 14 defaults.

What this means is that Paint can open a total of 14 different file types, but Paint is used for only 3 of them. There are another 11 file types it could potentially open, but some other program is set as the default.

To see which files Paint is used to open and which it isn’t, click Choose defaults for this program.

Look down the Extensions column to see which items are ticked. These are the file types for which Paint is the default. You can see that these are .emf, .rle and .wmf on this computer. If you wanted Paint to open any of the other file types such as .bmp, which as you can see are currently set to use Windows Photo Viewer, you would tick the box and click the Save button at the bottom.

If you didn’t want to use Paint for .emf files for example, do not clear the tick here. That would simply leave .emf as Not selected, like the .ico file extension in the list. Select a different program, one that can handle .emf files, and tick the .emf box in its extensions list.

It is a bit tedious, but you can select each program in turn and see which files it is set to be used with. Then you can modify the list if necessary. Just tick the file type boxes to steal the file extension from another program and prevent it from being used.