1st You download Webcam Driver.
Install driver for webcam a4tech After this install the Webcam driver in the system.
Installation of Webcam Driver
Go to the control panel
Click on the System Icon
Click on the Hardware Tab
Click on the Device Manager s
Select the Unknown Device or printer device where yellow Question Marks sign on it.
Right click on it and uninstall it.
After this go to the top of the device manager and click on scan for hardware changes.
Driver installation Wizard start.
Brows Your Driver from the Hard Disk and click on next.
Driver will be install.
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