I have a GPO that correctly edits the registry string for screensaver timeout here --> Computer\HKEY_CURRENT_USER\Control Panel\Desktop\ScreenSaveTimeOut
That works... however the screensaver still isn't behaving according to what the registry thinks it should be set at. For example, let's say either the GPO or I manually change the above registry string to 600 (10 minutes). Then I open Lock Screen Settings and from there click Screen Timeout Settings, it is actually still set to 3 minutes (and the screensaver starts after 3 minutes of idle). That's what I had manually set the GUI to a week or so ago. NOW the weird part is, if I change it in the GUI screen saver settings window to, let's say, 7 minutes and apply, and then go back to regedit and refresh, the string NOW says 420!?? So the GUI will write to the registry but changes in the registry (on that particular string value) seemingly have no affect on the GUI and more importantly on the reality of the setting. If the GUI is set to 3 minutes but the registry says 10 (600 sec)... the screen saver starts after 3 minutes. The GUI is the controlling factor and the registry is being ignored somehow.