First go to the device manager and check the "Imaging Device > Acer Web Cam" is available without any error. If not available, it may be a hardware issue. If available , try to uninstall webcam application and reinstall it. Please give me the feedback. Hope this will help you.
Please join me in congratulating IronFly who is the first Acer Community Member to achieve the rank of ACE Pathfinder. IronFly has shown a consistent willingness to help others and has worked hard to earn this new Rank. Congrats and Thank You IronFly.