Change the default app for a file type in Windows
Windows opens each file type with one default program. You can change it for a single type, for every type a program supports, or for links such as web pages and e-mail addresses.
With “Open with” (fastest)
Right-click a file of that type in Explorer, choose Open with → Choose another app, select the program and choose Always. From then on, every file with that extension opens in it.
In Windows 11 Settings
Settings → Apps → Default apps. Type the extension (for example .pdf) in the box at the top, select the current app below it and pick the new one. To give one program all the types it supports, search for the program instead and choose its file types one by one.
In Windows 10 Settings
Settings → Apps → Default apps → Choose default apps by file type. Find the extension in the list and click the program next to it to change it.
Links: browser and e-mail
Web links (http, https) and e-mail links (mailto) are protocols, not files. In Windows 11 set them under Settings → Apps → Default apps → the browser or mail program; in Windows 10 under Choose default apps by protocol.
When the program is not offered
A program appears in the list only if its installer registered the file type. Portable programs do not; choose “Choose an app on your PC” and pick its .exe file. Reinstalling the program with its installer also adds the missing registration.
Frequently asked questions
Why does Windows reset my default app?
Some updates and some programs reset associations they consider their own. Windows then shows a notification; setting the default again in Settings restores it.
Which program opens a given file type?
ExeAtlas has a page for each extension listing the Windows programs whose installers say they open it, with links to their official downloads.