Windows uses file associations to decide which app opens a file extension such as .pdf, .jpg, or .docx. If the wrong app takes over, you can switch it back in Settings or from the right-click menu.
These steps apply to Windows 10 and Windows 11.
Does This Affect You?
Use Settings when every file of that type should open in a new app. Use the right-click method when you want a quick change for one file type or only want to open one file differently this time.
Set a Default App by File Type
- Open Settings > Apps > Default apps.
- On Windows 11, search for the extension, such as .pdf or .png. On Windows 10, choose Choose default apps by file type and find the extension in the list.
- Click the current default app beside that extension.
- Choose the app you want to use instead.
- If the app is missing, use More apps or confirm the program is installed.
Choose an App from Open With
- Right-click a file of the type you want to change.
- Choose Open with > Choose another app.
- Select the app from the list.
- Check Always use this app to open files of that type if you want a permanent change. Leave it unchecked for one-time use.
- Click OK.
Extra Default App Notes
Reset Defaults
In Settings > Apps > Default apps, you can review defaults by app or reset Microsoft-recommended defaults if many associations are wrong.
Protocols Are Different
Links such as mailto: and tel: are protocols, not file extensions. They are controlled in the same Default apps area, but you search for the protocol name instead of a file type.
Apps May Take Defaults Back
Some programs re-register file associations after updates. If PDFs, photos, or media files suddenly open in the wrong app again, repeat the Settings method.
Sources
- Microsoft Support: Change default programs in Windows
- Microsoft Support: Change default apps and file type associations
- Microsoft Learn: Default app associations for Windows