Here’s a clear, step-by-step write-up for taking pictures on your computer, suitable for a help article, blog post, or quick guide. Whether you need a quick selfie, want to capture something on your screen, or are using an external webcam, your computer makes it easy to take pictures. This guide covers the built-in tools for both Windows and macOS. On Windows (Using the Camera App) Windows comes with a pre-installed Camera app that works with your built-in webcam or an external USB camera.