Webcam blockage

Trend Micro evidently turned off my webcam during the initial installation (I was queried about whether I wanted to keep hackers from using the camera). Now I cannot be seen by anyone when, for example, I participate in a Zoom meeting. How do I turn the web cam back on? I can turn the camera on and off in Zoom or in Settings but not really. In Zoom, turning the camera off causes my name to be placed in middle of blackened frame; turning it on, moves my name to the bottom of the blackened frame. Dell diagnostics indicate that the camera is fine and that there must be a software issue. Please help.