More laptops these days have built-in webcams. Although this provides a convenience for video conferencing without additional equipment, restarting a built-in webcam is not as straightforward a process as with an external one. There is often no physical power button on an internal webcam. Instead, use your system's control panel to restart your webcam.
Click the "Start" menu and click "Control Panel."
Click the link for "View devices and printers." It is located under the "Hardware and Sound" section.
Locate your webcam under "Devices" and right-click it. Select "Properties."
Click the "Hardware" tab at the top of the window and click the "Properties" button located at the bottom-left of the window.
Click the "Driver" tab and click the "Disable" button. Click "Yes" to confirm and turn off the webcam.
Click the "Enable" button to turn your webcam back on. The "Disable" button changes to "Enable" after the webcam has been disabled. Close out the webcam "Properties" windows, and restart your computer.
You can also access the webcam Properties window by right-clicking the "Computer" icon on the desktop and selecting "Properties." Click the "Device Manager" link on the left side of the window, and click the arrow next to "Imaging devices." Right-click your webcam and select "Properties."