function ActivateScreenSaver(Activate: boolean): boolean;
{ func to activate or deactivate the screensaver. }
var
IntActive: byte;
begin
{ False (0) is off, True (1) is on. }
if Activate then
IntActive := 1
else
IntActive := 0;
Result := SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, IntActive, nil, 0);
end;