Remote Assist...Cannot find checkbox to enable expert machine to take control

Hi,

The novice machine is running Vista HP, the expert machine is running
Windows 7 Pro. The user mode is admin for both.

My objective is to control the novice machine but thus far all I can do on
the expert machine is to view the novice machine desktop. I can watch what
the novice is doing but cannot initiate any actions from the expert machine.

The help menu on the novice machine tells me to check the box to enable the
expert to take control. I cannot find the box and suspect that the box
itself must be enabled elsewhere.

Thank you for any helpful information.

JB