Right-click the file and pick "Open with" to change it once, or use Settings to change it permanently
When you double-click a file, your computer has a default program assigned to open it — the one that launches automatically. You can override that choice in two ways: open a single file with a different program right now, or change which program always opens that file type going forward. The method depends on whether you want a one-time change or a permanent one.
On Windows, right-clicking any file shows an "Open with" menu that lists programs you can use immediately. On Mac, right-click (or Control-click) and select "Open With" to see the same options. If you want to make the change stick for every file of that type, you'll use your system settings instead — that's where the actual default assignment lives.
Key Takeaways
- Right-click a file and choose "Open with" to open it with a different program just that one time without changing your defaults.
- On Windows, go to Settings > Apps > Default Apps, find the file type, and click it to pick a new default program.
- On Mac, right-click the file, select "Open With", choose your program, then click "Change All" to make it the default for that file type.
- If a program doesn't appear in the "Open with" menu, you may need to install it first or manually browse to find it.
- Changing defaults for one file type (like .pdf) does not affect other types (like .docx).
Opening a single file with a different program on Windows
Right-click the file you want to open. A menu appears with several options. Look for "Open with" — it may show a submenu with program names, or it may say "Open with" followed by an arrow pointing to more choices. Click the program you want to use.
That file opens in the program you picked, but your default doesn't change. The next time you double-click a file of the same type, it will still open in whatever program was set as default before. This method is useful when you occasionally need a different program but don't want to change your everyday choice.
Opening a single file with a different program on Mac
Right-click (or Control-click) the file. Select "Open With" from the menu. A list of programs appears — these are applications your Mac thinks can open this file type. Click the one you want.
After you click, the file opens in that program. Your default setting stays the same. If you want to change the default for all files of this type, see the section below on making permanent changes on Mac.
Changing the default program permanently on Windows
Open the Settings app. Click "Apps" in the left sidebar, then click "Default Apps" near the top. You'll see a list of file types and programs — for example, ".pdf" might show "Microsoft Edge" as the current default.
Find the file type you want to change. Click on it. A window opens showing programs that can open that type. Click the program you want to use as the new default. Windows updates the setting immediately. The next time you double-click a file of that type, it will open in the program you just chose.
If the program you want doesn't appear in the list, scroll down to see more options, or look for a button that says "Look for another app on this PC" — this lets you browse your computer for a program that isn't shown by default.
Changing the default program permanently on Mac
Right-click (or Control-click) the file whose type you want to change. Select "Open With", then click the program you want to use. After the file opens, right-click the same file again, select "Open With", and look for a "Change All" button next to the program name. Click it.
Mac will now open all files of that type with the program you chose. If you don't see a "Change All" button, try this alternative: right-click the file, select "Get Info", find the "Open with" section, click the dropdown menu, choose your program, then click "Change All" at the bottom of that section.
What to do if your program doesn't appear in the list
On Windows, if a program you own isn't showing up in the "Open with" menu or in Settings, the program may not have registered itself with Windows during installation. Try reinstalling the program — during setup, look for an option that says "associate file types" or "set as default" and make sure it's checked.
On Mac, programs that can open a file type usually appear automatically in the "Open With" menu. If yours doesn't, the program may not support that file type. Check the program's documentation or website to confirm it can open the file type you're trying to use. If it should work but doesn't, try reinstalling the program.
On both systems, you can also manually browse for a program. On Windows, in the "Open with" menu, look for "Choose another app" or "More apps", then scroll to the bottom and select "Look for another app on this PC". On Mac, in the "Open With" submenu, select "Other" and browse to find the program's icon in your Applications folder.
Understanding file types and why defaults matter
Your computer identifies files by their extension — the letters after the dot in the filename, like .pdf, .docx, or .jpg. Each extension can have one default program assigned to it. When you change the default for .pdf files, you're only changing what opens .pdf files; .docx files keep their own separate default.
Defaults matter because they determine what happens when you double-click a file in your file manager or when a website or email tries to open a file. If you change your default to a program you don't use often, you may find yourself frustrated when files open in an unexpected place. It's worth thinking about which program you actually use most for each file type before making the change permanent.
Frequently Asked Questions
Can I set different default programs for the same file type?
No. Each file type can have only one default program at a time. You can change which one it is, but you can't have two defaults for the same extension. If you need to use multiple programs for the same file type, use the "Open with" method each time instead of changing the default.
Will changing a default affect files I already have?
No. Changing a default only affects how new files open going forward. Files you've already opened will remember which program you used last, but double-clicking them will use the new default you just set.
What if I change my mind and want to switch back?
Follow the same steps you used to change it the first time. Go back to Settings (Windows) or Get Info (Mac), find the file type, and pick the program you want instead. There's no limit to how many times you can change defaults.
Why does a program I installed not show up in the "Open with" menu?
Some programs don't register themselves with your operating system during installation. Try reinstalling the program and look for a checkbox during setup that says something like "associate file types" or "set as default". If that doesn't work, use the manual browse option to find the program yourself.
Can I set a default for a file type that no program on my computer can open?
No. You can only set a default to a program that's actually installed and can open that file type. If you need to open a file type your computer doesn't recognize, you'll need to install a program that supports it first.