Computer Lab Software question

I have a client that wants to setup a computer lab and wants to make it so that the main computer would be able to send their active screen to all the other computers so that they would see what he/she is doing. Also, the users would be unable to navigate away from the screen being displayed on their computer from the main.

My question is:

Is there any known programs out there that would enable my client to do this and do it without the other users having to authorize a connection. This would mean that the primary computer would in effect take control of the user pc display so that the user would be unable to navigate away from what the presentor wants to display on the screen. (This would be for approximately 10 users, all computers running WinXP SP2)


Thank you