How do I Black Screen ALL of the external connections to a remote computer except my session

Meir

We learned that a customer can log into their remote laptop from another computer in their lab at the same time that we are connected to the remote laptop and they can see EVERYRTHING that we are doing during our session. The screen is black on the remote laptop but not on their other computer in the lab.

How do we make the Black Screen for ALL of the external connections on the remote laptop except for our session for remote access?

Meir

We already followed this set of directions. The remote computer does have a black screen. However, the issue is that the customer can be logged into the remote computer with another laptop in another room and still see all of the changes that we are making on their remoter computer during our session. Is there a way to see if any other people are logged into the remote computer or if anyone logs into the remote computer during our session? Is there a way to log them out of the system while we do a remote session?