Controling the Power Option for Roaming

We have Windows 2000 Public computers locked down with manditory roaming profiles. The desktop has no access to the Control Panel. The problem is the Power Option in the Control Panel is setup to power off the monitor after 20 min. We have tried setting up the profile with Never on the monitor power option but after a time on the desktop, the screensaver starts & later the monitor goes black. I was trying to find a setting in the registry under Local Machine, but have had no luck. Any helpwould be appreciated. Thanks