Fix Zoom Error: "Cannot Start Video: Camera Is Being Used by Another App"

This error follows the same fundamental pattern as similar errors covered elsewhere on this site — only one application can typically hold an active camera connection at a time, and something else already has it. What makes Zoom's version worth its own dedicated guide is one specific, well-documented quirk in how Zoom itself behaves.

Zoom's desktop client doesn't always fully terminate when its main window is closed — a background process (visible in Task Manager or Activity Monitor as "zoom.us" or similar) can persist quietly, still technically holding the camera even though nothing appears open on screen. This means the "other app" using your camera can, confusingly, sometimes be Zoom itself from an earlier session you thought you'd already closed.

Beyond this Zoom-specific quirk, the usual suspects still apply: other video-calling software, browser tabs with an active camera stream, or antivirus webcam-protection modules can all produce this identical error.

Step 1: Open Task Manager (Windows: Ctrl+Shift+Esc) or Activity Monitor (Mac).

Step 2: Search for "zoom" specifically

And check whether any Zoom-related process is still running, even if you already closed the visible Zoom window.

Step 3: End that process directly

If found, then relaunch Zoom fresh.

Step 4: Check for other applications

That might be using the camera — other call software, browser tabs, or background utilities.

Step 5: Restart your computer

As a reliable fallback that clears any lock regardless of its source. ↑ Confirm the camera is free with the widget above before rejoining Zoom.

How do I reset the Windows Camera app itself?

Go to Settings → Apps → Installed apps, find Camera, open its three-dot menu, and choose Advanced options → Reset. This clears the built-in Camera app’s own cache and settings without uninstalling it, which can fix a stuck, frozen, or permanently black preview even when the underlying device and driver are both working correctly. It only resets that one app — not your camera driver, and not other applications that use the camera.

Could my antivirus be silently blocking my camera?

Many third-party security suites — Bitdefender, Kaspersky, Norton, and ESET among others — include their own webcam-protection feature that runs independently of Windows’ own privacy settings. That means Windows can show camera access as fully permitted while the antivirus software blocks it anyway, at a layer Windows has no visibility into. Check the antivirus program’s own settings, usually under a Privacy, Webcam Protection, or similarly named section, and confirm your browser or conferencing app is on its allow-list.

How do I re-enable my camera in Device Manager if it's disabled?

Right-click the Start button → Device Manager, expand Cameras or Imaging devices, and look for a greyed-out icon or a small down-arrow badge. Right-click that entry and choose Enable device. This is a different action from updating a driver — a disabled device won’t respond to any other fix until it’s explicitly re-enabled here first, so it’s worth checking before assuming the problem is a driver or a permission.

Is Windows' own camera privacy toggle blocking access, separately from anything else?

Windows keeps a system-level camera permission at Settings → Privacy & security → Camera, completely separate from Device Manager, the Camera app, and any antivirus software. This one screen has a master Camera access switch plus a per-app list beneath it — both need to be on. It’s worth checking directly, since a camera can show as fully enabled and working in Device Manager while this toggle silently blocks every app from reaching it.