Guide · Apps that quit

App keeps quitting on your Mac or Windows PC, or the computer restarted by itself? What to do

By the AI Repair team · Updated 31 October 2026

An app closes in the middle of your work, or your Mac greets you with “Your computer restarted because of a problem.” Either is usually fixable without losing anything. These steps go gentlest first, with the steps for a Mac and for Windows, then what to do when the whole computer restarts by itself.

1. Open the app again

One crash now and then happens to every app, and opening it again is often all it needs. On a Mac, a message says the app “quit unexpectedly”: click Reopen (Apple’s guide). The app may offer to bring back the windows you had open. Report sends the details to Apple; it doesn’t fix anything on your Mac.

If the app is frozen rather than closed, the pointer spins and nothing answers: choose Apple menu › Force Quit, or press Option ⌘ Esc, click the app, then Force Quit (Apple’s guide). Anything you hadn’t saved in it is lost.

On a Windows PC, the app’s window simply closes, sometimes with a message that it stopped working. Open the app again from the Start menu. If it’s frozen, press Ctrl Shift Esc to open Task Manager, click the app, then End task.

2. Restart your computer

A restart clears out whatever the app tripped over: a part of macOS or Windows that got stuck, or another program in its way. Save your work, then choose Apple menu › Restart on a Mac, or Start › Power › Restart on a Windows PC. When it’s back, open the app before anything else and see if it behaves.

3. Make room on your disk

Apps need free space to save their work as they go. When the disk is nearly full, they start quitting, freezing or refusing to save. On a Mac, choose Apple menu › System Settings › General › Storage to see how much is free; on macOS 12 Monterey, it’s Apple menu › About This Mac › Storage. On a Windows PC, choose Start › Settings › System › Storage.

With less than about 10 GB free, make room first: our guide to a full disk shows what is safe to delete.

4. Update the app

Most crashes are faults in the app itself, and its maker has often fixed them in a newer version. An app that quits right after you updated macOS or Windows is usually waiting for its own update.

• From the App Store: open the App Store, click Updates in the sidebar, then Update next to the app (Apple’s guide).
• From the maker’s website: open the app, click its name at the top left of the screen and choose Check for Updates; some apps have it in their Help menu. If it can’t stay open long enough, download the newest version from the maker’s website.
• On a Windows PC: apps from the Microsoft Store update in the Store: open it, click Library (Downloads in newer versions), then Get updates (Microsoft’s guide). Other programs usually have Check for updates in their Help menu, or a newer version on their maker’s website.

5. Update macOS or Windows

Updates fix faults in macOS and Windows that make apps quit, and a new version of an app may need a newer system. On a Mac, choose Apple menu › System Settings › General › Software Update; on macOS 12 Monterey, Apple menu › System Preferences › Software Update (Apple’s guide). On a Windows PC, choose Start › Settings › Windows Update, then Check for updates; on Windows 10, Start › Settings › Update & Security › Windows Update. Our guide to an update that won’t finish helps if it gets stuck.

If an app needs a newer macOS than your Mac can install, its maker’s website usually lists the last version that works on yours.

6. Turn off the app’s add-ons

Many apps load add-ons from other makers: plug-ins in a photo editor, extensions in a browser, add-ins in Word or Excel. When the app quits only when you do one thing, such as print, open a certain file or use a device, an add-on is often to blame, not the app.

1. Open the app, then its settings: on a Mac, click the app’s name at the top left of the screen, then Settings (Preferences in older apps); on a Windows PC, look in its File, Tools or Options menu.
2. Look for Extensions, Plug-ins or Add-ons, and turn off the ones you added most recently, or don’t need.
3. Use the app as before. If it stops quitting, turn the add-ons back on one at a time to find the one at fault, then check its maker’s website for a newer version, or leave it off.

7. Install a fresh copy of the app

A damaged app keeps quitting however often you open it. Sometimes macOS says so itself: that the app “is damaged and can’t be opened”. A fresh copy fixes it, and your documents are kept: they aren’t stored inside the app.

On a Mac:

1. Quit the app.
2. In the Finder, click Applications in the sidebar and drag the app to the Trash. Your Mac may ask for its password.
3. Download the app again: from the App Store, search for it and click the download button; otherwise, from its maker’s website. Then open it, and sign in again if it asks.

If the app came with an uninstaller, use that instead of the Trash: our guide to removing an app explains when.

On a Windows PC, let Windows repair it first (Microsoft’s guide):

1. Choose Start › Settings › Apps › Installed apps (on Windows 10, Apps & features).
2. Click the three dots next to the app (on Windows 10, click the app). If you see Advanced options, click it, then Repair; if you see Modify, click it and choose the repair it offers.
3. If neither is there, or the app still quits, click Uninstall, then download the app again from the Microsoft Store or its maker’s website.

8. See which apps quit, and when

When it’s more than one app, or you’re not sure which, your computer keeps a record. It helps to see whether the trouble started on a certain day, after an update or a new program.

On a Windows PC, click Start, type reliability, and open View reliability history. Each day with a red cross had a problem: click it to see which app “stopped working”, or whether Windows itself shut down unexpectedly.

On a Mac, open Console from Applications › Utilities and click Crash Reports in the sidebar: each report is named after the app, with the date. The reports themselves are written for the app’s maker, so you don’t need to read them.

If your Mac restarted by itself

When macOS hits a problem it can’t recover from, it restarts the Mac to protect your files, then says your computer restarted because of a problem (Apple’s guide). Once in a long while is nothing to worry about. If it keeps happening:

1. Update macOS, as in step 5.
2. Update or remove software from other makers that works deep inside your Mac: for a printer, scanner or audio device, a graphics tablet, antivirus or a VPN. Check each maker’s website for a version for your macOS, and remove what you no longer use with its own uninstaller.
3. Unplug everything but the power: hubs, docks, drives, printers and adapters. Use your Mac like that for a day or two. If it doesn’t restart, plug them back in one at a time, a day apart, to find the one that causes it.
4. Try safe mode. It starts your Mac without some login items and extensions (Apple’s steps). On a Mac with Apple silicon, shut down, press and hold the power button until the startup options appear, select your startup disk, then hold Shift and click Continue in Safe Mode. On an Intel Mac, hold Shift as it starts up and let go at the login window. If it doesn’t restart in safe mode, something that starts with your Mac normally is the cause. Restart as usual to leave safe mode.
5. Check the hardware with Apple Diagnostics (Apple’s steps). On a Mac with Apple silicon, shut down, press and hold the power button until the startup options appear, then press ⌘ D. On an Intel Mac, hold D as it starts up. Write down any reference code it shows.

A Mac that gets very hot can restart too: use it on a hard, flat surface, never on a bed or a cushion, with its vents clear.

If your Windows PC restarted by itself

When Windows hits a problem it can’t recover from, it shows a blue screen, black on the newest Windows 11, that says your device ran into a problem and needs to restart (Microsoft’s guide). If it keeps happening:

1. Update Windows, as in step 5. Then choose Advanced options › Optional updates in Windows Update (View optional updates on Windows 10) and install any driver updates offered.
2. Unplug everything you don’t need, such as drives, hubs and docks, and see if it stops. Then plug them back in one at a time.
3. Remove what you installed just before it started, in Start › Settings › Apps › Installed apps.
4. Look at the reliability history, as in step 8: “Windows was not properly shut down” on the same days as an app or a driver that stopped working points to that one.

A PC that restarts with no message at all may just be installing updates outside your active hours, or may have lost power: check Update history in Windows Update for that night.

When to ask for help

If one app still quits after an update and a fresh copy, its maker can find out why from its report: look in the app’s Help menu or on the maker’s website for support. If your computer keeps restarting with nothing plugged in and all its updates installed, or Apple Diagnostics finds a problem, it may be the hardware: Apple, an Apple Authorized Service Provider, or your PC’s maker can test it.

Advice you can skip

• Reinstalling macOS or resetting Windows because of one app. It takes hours, and the steps above fix the app without touching the rest of your computer.
• A cleaner or “speed-up” app. Apps don’t quit because of junk files, and cleaners can delete what an app needs. Our guide on cleaner apps says when one helps.
• Deleting an app’s files from your Library or AppData folder by hand, as some websites suggest. It can lose your settings, or more, with no undo.
• Calling a phone number from a pop-up that says your computer crashed or is infected. Apple and Microsoft don’t put phone numbers in their error messages: see our guide to fake virus warnings.

Common questions

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