@Flood and Flood's wife Sorry, I'm not an expert on KTS, so maybe I didn't make it clear. I saw the black screen I have searched and read related topics, but can't solve my problem In KTS Reports, no any web camera events I have two NBs, one has this trouble and the other is normal My Win7 NB been shutdown & restarted many times, but not help Same problem on both browsers (Chrome and Firefox) The major app is Google Meet, but other app also fail I have checked KTS, Settings, Even webcam protection ON or OFF, I always got the black screen