Change remote control permissions in Windows 2008 terminal services using group policy.
Open the Group Policy applet.
Navigate through Computer Configuration --> Administrative Templates --> Windows Components.
Select Terminal Services.
In the righthand pane, double-click the "Set Rules for Remote Control of Terminal Services User Sessions" setting, and then click Enabled.
In the Options box, click the desired remote control permissions as described previously. Or, to disallow remote control, click No Remote Control Allowed.
Click OK to complete the procedure.