In addition my hotkeys for brightness control sort of black out as well. According to Microsoft then the brightness should be controllable under the Power option panel (sliding bar) but this was not visual when I tried it out the first time. Had exactly the same brightness (or lack) as discussed above. Have a t400 and just installed windows 7. I hope that resolves the issue Edit #2: Finally, it worked, I installed the drivers for the nVidia GeForce 8400M and also the latest Chipset drivers from Intel 900 series. I'm still looking for a solution :S Edit: I'm going to download the chipset drivers from the Intel website and also the win7 nVidia drivers for the GeForce 8400M. The brightness control worked when I had Vista installed. My BIOS doesn't allow me to change any settings regarding brightness, I can't find it anywhere! In the Boot tab of the BIOS I only get a list of: Hard Disk, CD Rom, USB and some other devices, but nothing related to brightness, thus, this solution doesn't work for me, screen is about 75% bright, its bearable, but not for my taste, and I can't dim it all the way down using Power Saver plan or put it all the way up in High performance plan because the control won't show on Power Plan settings (not even in advanced power settings). it will show the little progress bar but the brightness itself doesn't change. I managed to install Dell's Quickset app, all keyboard functions work now, except the brightness. Unfortunately, if there’s no physical adjustment control, no secondary keyboard control, and no software control for brightness, then I’m not aware of a way to adjust it.I'm using a Dell Vostro 2510, and just installed Windows 7 Ultimate. You might also like to turn off the “Adjust my screen brightness automatically” option if you find that the brightness is changing in ways that don’t work for you. If it is present and enabled, then naturally, you can adjust the brightness as you like. Not all displays allow for their brightness levels to be adjusted using software. It may not be there, or it may not be enabled. On the resulting page, there may be something called Adjust brightness or Brightness level.In the left-hand column, choose Display.Right-click on the desktop and choose Personalize.
If you have the correct drivers (in other words, if your video-card drivers support this), it’s sometimes possible to adjust the brightness in Windows itself. Regardless, you’ll need to hold down another key, often a “Fn” key, to use the secondary functions. The secondary functions are occasionally printed in a different color, such as blue. In most cases, these “secondary functions” use the same keys as other functions, like the up/down arrows pictured above. Use in conjunction with “Fn” or other modifier key to adjust brightness. An example of brightness-adjustment keys. The exact sequence varies based on what laptop you have.
Instead, there may be a key sequence that can change the brightness for you. If you’re using a laptop, you or may not have actual physical controls.