Most laptops come with a small webcam built into the top of the screen, perfect for video chatting. But Windows Vista and newer operating systems don't have a way to just open this webcam on the screen and view what it sees. Most of the time, you can just run a program that uses the webcam to check whether it works. If not, there are a few other things you can try.
Run a program that uses a webcam, such as Skype or Yahoo! Instant Messenger. See if the camera works in that program.
Visit the computer manufacturer's website. Look for the link to the "Support" department and click on it. Click on the link to "device drivers." Select your computer model, or type it in, and find the link for a device driver for the webcam. Follow the instructions to download and install it.
Click on the "Control Panel" section of the "Start" menu and click on the "Device Manager" section. Find the webcam in the list of devices and see if there is a yellow exclamation mark next to it. If so, reboot the computer to see if this fixes the problem. If it doesn't, consult the manufacturer's technical support staff.