How to fix Camera app error 0xA00F4240 in Windows?
Prefer to fix it yourself? The manual steps follow.
- 8methods
- 5 to 30 minutes
- Easy
Applies to Windows 11, Windows 10; the Windows Camera app with built-in laptop cameras and USB webcams
8 methods in this guide
I have recently run into an annoying issue with my laptop's camera. Every time I try to use it, I receive the error code 0xa00f4240 <Unknown> (0x80070057). As a result, I can no longer take pictures or do anything else with the camera or the Camera app. Please advise on solutions. I am using Windows 10, and my laptop is a Dell Inspiron.
Error 0xA00F4240 <Unknown> appears when the Windows Camera app tries to open your webcam and Windows returns a failure the app has no name for. The camera is usually fine. Check camera access and any camera switch first, then roll back or reinstall the camera driver.
The Camera app asked Windows for the camera and got a failure without a known name, so it shows <Unknown> and the Windows code in brackets. First turn on camera access for the device, for apps and for the Camera app, and check any camera key or shutter (Fix 1 and Fix 2). If the camera still fails, roll back or reinstall its driver (Fix 3).
| Error | Something went wrong, "If you need it, here's the error code:" 0xA00F4240 <Unknown> (0x80004003). The code in brackets can also be 0x80070057, 0x80131502 and others. |
|---|---|
| Where it appears | In the Windows Camera app, right when it opens or when it tries to show the preview. The screen stays black or grey with the message. |
| Main cause | Windows could not hand the camera to the app: camera access is off, the camera is switched off or blocked, or its driver is damaged or changed by an update. |
| Fastest fix | Turn on Camera access, Let apps access your camera and the Camera app switch in Settings, then restart (Fix 1). |
| Also written as | 0xa00f4240, a00f4240, 0xA00F4240<Unknown>, 0xA00F4240 <Unknown> (0x80004003), 0xa00f4240 unknown, camera error code 0xa00f4240. |
| Affects | Windows 11 and Windows 10, built-in laptop cameras and USB webcams. Reports we saw name Dell and Acer laptops and generic USB UVC webcams. |
| Microsoft's status | No Microsoft article for 0xA00F4240. Microsoft's camera page lists the named codes, such as 0xA00F4244 (camera not detected) and 0xA00F4246 (camera locked by security software). |
| Where the cause shows | No log names this code. Device Manager tells most: a missing camera, a warning sign, or a driver date that changed when the error began. |
| Time to fix | 5 minutes for the settings and switch checks, up to 30 minutes for a driver change. |
Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.
What camera error 0xA00F4240 <Unknown> means
The message comes from the Windows Camera app. A user with a USB webcam quoted it in full on Microsoft's Q&A forum in August 2026: Something went wrong, then "If you need it, here's the error code:" and 0xA00F4240 <Unknown> (0x80004003). That user's webcam was detected correctly by Windows, and the app still failed.
The Camera app gives its errors a code and a short name in angle brackets, such as 0xA00F4244 <NoCamerasAreAttached>. Here the name is <Unknown>: the app asked Windows for the camera, got a failure back and has no name for it. The second code in brackets is the result Windows returned.
| Code in brackets | What it is | What it tells you |
|---|---|---|
| 0x80004003 | E_POINTER, an invalid pointer. | The most common pair in the reports we read. Windows handed the app no usable camera object. Start with Fix 1, then Fix 3. |
| 0x80070057 | E_INVALIDARG, an invalid parameter. | The camera or its driver did not accept what the app asked for. Driver first (Fix 3, Fix 4). |
| 0x80131502 and others | We could not confirm a camera-specific meaning. | Work through the fixes in order. The first steps are the same. |
People search the same error as 0xa00f4240, a00f4240, 0xa00f4240 unknown, camera error code 0xa00f4240 or 0xA00F4240<Unknown>(0x80004003). The code is the same in every spelling and in every language of Windows; only the words around it are translated. A different code has a different first fix: for the camera switch error, see our guide to error 0xA00F4241.
Open another app that uses the camera, such as Teams or a webcam test in your browser. If the camera works there, the fault is in the Camera app (Fix 5). If it fails everywhere, the cause is settings, a switch or the driver (Fix 1 to Fix 4).
Why the Camera app shows error 0xA00F4240
Most often camera access is off for the device, for apps or for the Camera app itself, which Microsoft lists first after a Windows update. Often the camera is switched off by a key, a slider or a shutter, or the driver was changed by an update. Less often the Camera app is damaged or security software blocks the camera.
| Cause | How often | How to tell | Fix |
|---|---|---|---|
| Camera access turned off in privacy settings, or not allowed for the Camera app. | Most often | The camera works in desktop apps such as Teams, but not in Camera. Or it fails in every app after an update. | Fix 1 |
| Camera switched off by a key, a slider or a shutter, or a USB webcam is loose. | Often | The camera is missing from Device Manager, or the preview shows a camera with a slash. | Fix 2 |
| Camera driver changed or damaged by an update. | Often | A warning sign in Device Manager, or the driver date matches the day the error began. | Fix 3 |
| A USB webcam works poorly with its maker's driver. | Sometimes | External webcam, detected by Windows, fails in every app. | Fix 4 |
| The Camera app is damaged or outdated. | Sometimes | Other apps show the camera normally. | Fix 5, Fix 6 |
| Security software blocks the webcam. | Rarely | Your security suite has a webcam protection feature that is on. | Fix 8 |
How to fix Camera app error 0xA00F4240
Fixes 1 and 2 check what stops Windows from handing over the camera at all, and they cost a few minutes. Fixes 3 and 4 repair the driver. Fixes 5 and 6 repair the Camera app when other apps see the camera. Fixes 7 and 8 are the general checks Microsoft lists for any camera error.
| What you see or have | Start with |
|---|---|
| The error started after a Windows update, or you are not sure the privacy switches are on. | Fix 1 |
| The camera is missing from Device Manager, or the preview shows a camera with a slash. | Fix 2 |
| The camera has a warning sign in Device Manager, or the error began after a driver update. | Fix 3 |
| External USB webcam that Windows detects but no app can use. | Fix 4 |
| The camera works in Teams or a browser, only the Camera app fails. | Fix 5, then Fix 6 |
| Your security suite has webcam protection. | Fix 8 |
Fix 1. Turn on camera access for the device, for apps and for the Camera app
5 minutesNo riskEveryone, first. Especially when the error appeared after a Windows update or a new security policy.
Microsoft says that after a Windows update some apps may lose default access to the camera. When access is off, Windows does not give the camera to the Camera app, and the app can only report a failure it has no name for.
- Open Start > Settings > Privacy & security > Camera.
- Make sure Camera access is turned on.
- Make sure Let apps access your camera is turned on.
- In the app list below it, turn on Camera.
- Turn on Let desktop apps access your camera too, so you can test the camera in Teams or a browser later.
- Open Settings > Apps > Installed apps, select the three dots next to Camera, then Advanced options, and check that Camera is on under App permissions.
- Restart the PC with Start > Power > Restart and open the Camera app again.
On Windows 10 the path is Settings > Privacy > Camera. If Camera access for this device is off, select Change and turn it on. If the switch is greyed out, Microsoft says an administrator of the PC, or your work or school policy, must turn camera access on for you.
It worked if: All switches are on, and after the restart the Camera app shows the live preview.
If not: If the switches were already on, check that the camera itself is switched on and connected. Go to Fix 2.
Fix 2. Check the camera key, slider or shutter and the connection
5 minutesNo riskThe camera is missing from Device Manager, the preview shows a camera with a slash, or you use a USB webcam.
Microsoft notes that many laptops have a switch or key that turns the camera off. When it is off, the device may not recognise that a camera is installed, so the app cannot open it.
- Look for a sliding switch on the side of the laptop and set it to on.
- Look for a key with a camera icon, often in the top row of the keyboard, and press it once. Some laptops need Fn together with that key.
- Check for a small shutter slider over the lens at the top of the screen and slide it open.
- For a USB webcam, unplug it, plug it into another USB port directly on the PC, not a hub, and wait a few seconds.
- Right-click Start, select Device Manager and look under Cameras, Imaging devices or Sound, video and game controllers.
- If the camera is not listed, select Action > Scan for hardware changes, then open the Camera app again.
To rule out a faulty USB webcam, Microsoft suggests testing it on a different PC. If it fails there too, the webcam itself is the likely cause.
It worked if: The camera appears in Device Manager without a warning sign, and the Camera app shows a picture.
If not: If the camera is listed but the error stays, its driver is next. Go to Fix 3.
Fix 3. Roll back or reinstall the camera driver
10 minutesLow riskThe camera has a warning sign in Device Manager, or the error began after a Windows or driver update.
Microsoft's camera page gives roll back first when a camera stopped working after an update, then uninstall and scan for hardware changes. A fresh driver clears the bad state that makes Windows return an invalid result to the app.
- In Device Manager, right-click the camera and select Properties.
- Open the Driver tab and note the Driver Date and Driver Version.
- If the error began after an update and Roll Back Driver is available, select it, then Yes. Restart and test.
- If it is greyed out or did not help, select Uninstall Device, tick Attempt to remove the driver for this device and select OK.
- Select Action > Scan for hardware changes, wait for the camera to come back, restart the PC and open the Camera app.
A laptop maker's support page often has a newer camera driver than Windows Update. Full driver steps: Update, roll back or reinstall a driver
It worked if: The camera is listed again without a warning sign, and the preview appears in the Camera app.
If not: For a USB webcam, go to Fix 4. For a built-in camera, go to Fix 5.
Fix 4. Switch a USB webcam to the USB Video Device driver
5 minutesLow riskThe camera is an external USB webcam that Windows detects, and no app can use it.
Most USB webcams follow the USB Video Class standard and work with the driver built into Windows. Microsoft suggests this swap when a webcam does not work correctly, and the August 2026 report of this error came from exactly such a UVC webcam.
- Open Device Manager and find the webcam under Cameras or Imaging devices.
- Right-click it and select Update driver.
- Select Browse my computer for drivers.
- Select Let me pick from a list of available drivers on my computer.
- Select USB Video Device, then Next, then Close. Open the Camera app.
The built-in driver may not support every feature of your webcam. Microsoft warns that Windows Hello face sign-in can stop working. To go back, use Roll Back Driver on the Driver tab.
It worked if: The webcam appears under Cameras as a USB Video Device, and the Camera app shows a picture.
If not: If USB Video Device is not offered, the webcam does not follow the standard. Go on to Fix 5.
Fix 5. Repair or reset the Windows Camera app
5 minutesLow riskThe camera works in Teams, a browser or another app, and only Windows Camera shows 0xA00F4240.
When another app can use the same camera, the hardware, driver and privacy switches are fine. The fault then sits in the Camera app, and a reset puts its settings back to default without touching your photos.
- Close the Camera app.
- Open Settings > Apps > Installed apps, find Camera, select the three dots and select Advanced options.
- Select Terminate to stop any hung Camera process.
- Select Repair if it is there, then open the Camera app.
- If it still fails, select Reset. The app's own settings go back to default; your saved photos and videos stay.
Full steps for Windows 11 and Windows 10: How to repair or reset an app in Windows
It worked if: The Camera app opens with default settings and shows the preview.
If not: If the error survives a reset, register the app again in Fix 6.
Fix 6. Register the Camera app again with PowerShell
10 minutesLow riskRepair and Reset did not help, and other apps still use the camera normally.
Registering the app again reads its manifest from the install folder and repairs how Windows knows the app. It helps when the app's registration is damaged, which a reset does not always fix.
- Right-click Start and select Terminal (Admin) on Windows 11 or Windows PowerShell (Admin) on Windows 10, then select Yes.
- Paste the command below and press Enter.
- Wait until the prompt returns, close the window and open the Camera app.
- If the app is still broken, open Microsoft Store, search for Windows Camera and install or update it.
Register the Windows Camera app again
Get-AppxPackage -allusers Microsoft.WindowsCamera | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
Your photos and videos are files in Pictures > Camera Roll, not app data, so this does not delete them. Another way to do it: How to re-register Microsoft Store apps with PowerShell
It worked if: The command ends without red error lines, and the Camera app opens with a picture.
If not: If the error stays, install pending updates and run the troubleshooter in Fix 7.
Fix 7. Install optional updates and run the Camera troubleshooter
15 minutesNo riskThe fixes above did not help, or Windows has updates waiting.
Microsoft's first steps for any camera error are camera drivers offered as optional updates and its camera troubleshooter. They are general, so they come after the checks that fit 0xA00F4240.
- Open Settings > Windows Update and select Check for updates.
- Select Advanced options > Optional updates and install any camera driver offered.
- Restart the PC. Waking it from sleep is not the same thing.
- Open Settings > System > Troubleshoot > Other troubleshooters and select Run next to Camera.
- Follow the troubleshooter, then open the Camera app.
If Windows Update itself fails: Run the Windows Update troubleshooter
It worked if: Windows is up to date, the troubleshooter reports what it checked, and the camera opens.
If not: If you use third-party security software, check its webcam protection in Fix 8.
Fix 8. Check the webcam protection of your security software
5 minutesLow riskYou use a third-party security suite with a webcam or privacy protection feature.
Microsoft says some antivirus programs and firewalls can block camera access. A blocked camera usually shows 0xA00F4246, but an app that cannot read the camera at all may report it as unknown.
- Open your security software and look for a setting called webcam protection, camera protection or privacy protection.
- Allow the Windows Camera app there, or add it to the trusted apps.
- Open the Camera app again.
- If you cannot find the setting, pause protection for one test only and turn it back on right away: Turn off Microsoft Defender protection for a moment
Pausing is a test, not a fix. If the camera works while protection is paused, turn protection back on and allow the Camera app in the webcam setting, or ask the security software maker how to do it.
It worked if: The security app lists Camera as allowed, and the Camera app opens with protection on.
If not: Read "If error 0xA00F4240 is still there" below and gather the details for support.
If error 0xA00F4240 is still there
The Camera app shows only the code, and we found no Windows log that names it. Three short tests tell you which part to take to support. Each one takes a minute.
- Test the camera in another app, such as Teams or a webcam test in your browser. If it works there, the fault is in the Camera app; you can use the other app meanwhile.
- Open Device Manager and check whether the camera is listed and whether it has a warning sign. A camera that disappears after Scan for hardware changes points to hardware or the camera switch.
- Start Windows in safe mode and open the Camera app once. If it works there, a startup program or a third-party driver gets in the way: Start Windows or a Mac in Safe Mode
- What to send to support: the full message with both codes, the camera name and driver version from Device Manager, the PC or laptop model, and the Windows version from Settings > System > About.
- Who to ask: for a built-in camera, the laptop maker. For a USB webcam, its maker. Microsoft says to look for help on the camera maker's website when the driver steps fail.
- When it is hardware: no app can use the camera, it is missing from Device Manager with the switch and shutter open, or a USB webcam also fails on a second PC.
How to keep the camera error from coming back
- Check Settings > Privacy & security > Camera after every large Windows update.
- Take camera drivers from your laptop maker, the webcam maker or Windows Update.
- Note the camera driver version that works, so you can return to it if a new one breaks the camera.
- Restart, not just wake from sleep, after any driver change.
- Do not install driver updater programs from unknown sites.
- Do not leave a camera key or shutter closed and forget it.
- Do not turn off your security software for good to get the camera working.
Windows 10 left support on 14 October 2025, so its Camera app and drivers no longer get regular fixes. If you still see 0xA00F4240 on Windows 10 after every fix, moving to Windows 11 brings a current Camera app and driver updates.
Frequently asked questions
What does error 0xA00F4240 <Unknown> mean?
It means the Windows Camera app asked Windows for the camera and got a failure it has no name for, so it shows <Unknown>. The code in brackets, such as 0x80004003 or 0x80070057, is the result Windows returned. In the reports we read, the cause is nearly always camera access settings, a camera switch or the camera driver, not a broken camera. Start with the privacy switches in Fix 1, then the switch and driver checks in Fix 2 and Fix 3.
How do I fix 0xA00F4240 on Windows 11?
Open Settings > Privacy & security > Camera and turn on Camera access, Let apps access your camera and the Camera app. Restart the PC. If the error stays, check the camera key or shutter, then open Device Manager, roll back or reinstall the camera driver and select Scan for hardware changes. For a USB webcam, try the USB Video Device driver. If other apps can use the camera, repair or reset the Camera app in Settings > Apps > Installed apps.
Is the fix different on Windows 10?
The fixes are the same, only some paths differ. On Windows 10 the privacy switches are in Settings > Privacy > Camera, where you may need to select Change to turn on camera access for the device. Apps are in Settings > Apps > Apps & features, and the PowerShell entry in the Start right-click menu is Windows PowerShell (Admin). Windows 10 left support on 14 October 2025, so new Camera app and driver fixes reach it less often.
What is 0xA00F4240 <Unknown> (0x80004003)?
It is the most common form of this error. 0x80004003 is the general Windows code E_POINTER, an invalid pointer. In plain words, Windows did not hand the Camera app a camera it could use. One user on Microsoft's Q&A forum saw it with a USB UVC webcam that Windows detected correctly. For that case, check the privacy switches first, then reinstall the camera driver or switch to the USB Video Device driver (Fix 1, Fix 3, Fix 4).
Is my webcam broken if I see camera error 0xA00F4240?
Usually not. If the camera is listed in Device Manager and works in another app, it is fine. Hardware is likely only when no app can use the camera, it is missing from Device Manager with any camera key, slider and shutter open, or a USB webcam also fails on a second PC. For a built-in laptop camera under warranty, contact the laptop maker. For a USB webcam, a replacement is often cheaper than a repair.
Will resetting the Camera app delete my photos and videos?
No. Your photos and videos are ordinary files in Pictures > Camera Roll. Reset clears only the app's own settings, such as photo quality and grid lines, and the Windows Settings page says uninstalling an app does not affect your documents. Registering the app again with PowerShell also leaves your files where they are. If you want to be safe, copy the Camera Roll folder to another drive or to OneDrive before you start Fix 5 or Fix 6.
Should I turn off my antivirus to fix the camera error?
Not as a fix. Microsoft lists security software as a possible camera blocker, and ties it mainly to a different code, 0xA00F4246. Look for a webcam protection setting in your security suite and allow the Camera app there. If you want to test with protection paused, do it for one test only and turn it back on right away, as Fix 8 explains. Leaving protection off is never the answer to a camera error.
The camera works in Teams or Zoom but not in the Camera app. Why?
Then the camera, its driver and the device-wide switches work, and the problem sits in the Camera app or its own permission. Check that Camera is switched on under Let apps access your camera, because desktop apps such as Teams use a separate switch. Then repair or reset the Camera app (Fix 5) and register it again with PowerShell if needed (Fix 6). You can keep using the other app until the Camera app works.
I searched in Spanish, Portuguese or Italian. Does this page fit?
Yes, if your screen shows 0xA00F4240. Searches such as error 0xa00f4240 en la aplicación cámara, erro 0xa00f4240 camera or codice errore 0xa00f4240 mean the same error. The code is identical in every language of Windows; only the text around it is translated. This page uses English menu names, which sit in the same places in other languages, for example Settings > Privacy & security > Camera.
Sources
- Microsoft Support: Camera doesn't work in Windows (privacy settings, camera switch, drivers, UVC driver, troubleshooter, error code table) (support.microsoft.com)
- Microsoft Q&A: Windows Camera app shows error 0xA00F4240 (0x80004003) with a correctly detected USB UVC webcam (full message) (learn.microsoft.com)
- Microsoft Q&A: My camera app is showing 0xA00F4240 (0x80004003) error (troubleshooter, driver, reset answers) (learn.microsoft.com)
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