Process and documentation for a easy to handle webinar recording

We search for an windows expert who is able to create us a simple to use process for creating videos from any webinar or online video/audio session. Assume you watch any arbitrary video on any arbitrary webpage or application and we want to be able to record this video incl. the audio. Mostly we need it for any webinar, which is not published afterwards as a reconsumable video. In this case we want to be able to review the webinar and recheck our notes from the webinar. So far we have tested some applications but they sometimes fail on video and sometimes on audio. Your job is to: - find a solution - ideally open source application - establish a simple process for any non experienced windows user - document this process, so any non experienced user can easily follow your documentation step by step (with screenshots) - in the recorded video also the video of the webinar has to be integrated. It is no option if the audio of the surroundings (with the computer mic) will be included - persons have to be able to discuss during the recording session. The solution has to work well on: - windows 7 - windows 10 we search also for a linux solution. so if you have a linux solution too, let us know