Precision 5510 - Screen very bright at lowest setting

I am using Windows 7. I was not able to see this option when I searched. Do you have instructions for WIn7?

Since your post doesn't say which OS you are running.  Here's some information for Windows 10:  

Windows can adjust the brightness of the display based on how much light is reaching the system's ambient light sensor. This feature is referred to as 'adaptive brightness' and it can be disabled in Windows.
•For Windows 10 1.In the Search box, type Settings.
2.Touch or click Settings (Modern application).
3.Touch or click System.
4.On the Display screen find the Adjust my screen brightness automatically option.
5.Touch or click the slider to toggle the option on or off.
6.Touch or click Apply.
7.Close the System window.

For Windows 8(8.1)
If you are using the Windows Modern User Interface (MUI): 1.Swipe from the right and touch Settings.
2.Touch Change PC Settings.
3.On the PC Settings screen, touch PC and Devices.
4.Touch Power and Sleep.
5.At the top of the screen will be a toggle for Brightness. Slide the toggle to the Off position to disable adaptive brightness.

I'm not finding the information for Windows 7 either, however, here is a program some users have reported successful.  You could give it a try.

http://dell.to/2fSg9Uz

Perhaps it would.  I'll be sure to mention it at our next team meeting.  Thanks.