I am using a windows 7 Acer laptop, and the screen only brightens when I plug in the charger. Also, the battery gets used up too quickly, even though I have the computer on 'power saver.' Downloading Bios or a brightness control won't work. The lever goes up and down easily when I bring up the 'adjust screen brightness' screen in the utility folder, but the screen stays dark. On top of that, the lever refuses to budge when I bring it up from the taskbar. Does anyone else have this problem? Please help!