How to disable automatic lock / log-out

Hello,

After countless hours searching online and into the depths of Vista, I've
nearly given up. I cannot figure out how to disable the occurrence of Windows
Vista Beta 2 automatically locking the computer after 10 minutes of
inactivity. I've completely disabled any sleep features, and the option
"require password after recovery from sleep", and nothing seems to do it.

In the process I've basically disabled every security feature present in
this new OS, just out of shear desperation. I display presentations that may
not have keyboard / mouse input for two hours, but the monitor is still being
viewed. I do not want the automatic log-out to occur at all.

I hope I've just overlooked some very simple adjustment, because I really
love Vista otherwise, despite its current kinks.

Sincerely,

William C

P.S. A big fat thanks to anyone in advance who can answer my question.