How XProtect Screen Recorder works
Once installed, XProtect Screen Recorder is automatically controlled from the startup menu of the computer where it is installed and runs in the context of the user logged into this computer. This means that XProtect Screen Recorder automatically and invisibly starts up every time the user logs in to the computer and closes down every time the user closes down.
If online user-switching is done via Window's Fast User Switching feature, the XProtect Screen Recorder will continue to record in the context of the new user, however any other type of user-switching/-logging in or out will result in discontinuation of the feature. Read more about switching users without logging off on https://www.technipages.com/windows-10-enable-or-disable-fast-user-switching/.
This is possible because it is a service running in the background, capturing the computer’s screen at a set frame rate. It is also this service that provides the interface that your XProtect surveillance system can connect to and retrieve images from similarly as any other camera.