The Windows Mobility Center (displayed when you press +X) normally shows a slider control for adjusting the brightness of the display on laptops. On my older Dell laptop this worked fine, but on my new HP Pavillion dm4t, the slider is absent. There is also no adjustment in the Power Settings in the Control Panel, like there usually is.
Windows has some ability to adjust the brightness, because the display automatically dims after a configurable amount of time. I can adjust the brightness using the hotkeys on the keyboard, which are controlled by an HP driver I have installed, but I would still like to be able to adjust this from within Windows.
Does anybody know how to get this working? Is there another driver package I need to install? Is there some registry setting I can set up in Windows to get it to work? Does anybody else have a recent HP laptop who can confirm if they have this problem as well? Thanks.