If you connect multiple monitors to your computer, it is also possible to choose which one you will record from. Depending on the app you are using, the process may differ slightly. In essence, you will have to go to the list of the video sources your software recognizes and select the specific monitor you want. If the software does not recognize your second monitor by default, you might need to add it. You do that by adding a new source to your recording software and assigning the monitor you want to capture to that source.