Unable to adjust the brightness of display screen

go to start->control panal->display->on the left hand upper corner there is an option adjust brightness.........if unable to find then click on start->search->adjust brightness(for windows 7)

are you pressing the Function key first? the brightness buttons do not work without pressing that first. usually it is in blue close to the ALT.
& Win key
You can also change your brightness from the control panel, click on display then color setting, and you can see the contrast and brightness, as well as gama that does make it brighter or darker as well. Remember to write down the default settings.
these will not affect playing movies, the brightness adjustment for that are different controls, they can be access by the right click on the mouse during playback

Tony

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/tony_a41fa0b801734e2f

there is some issue with ur display drivers try to uninstall it from safemode and again reinstall it back??

This is one of the worst sorts of failures darling.

Look for a key labeled "Fn" (blue lettering) on the lower left side of the keyboard

Hold the "Fn" key and then use the Up/Down arrows to adjust brightness.

If that doesn't work, reboot your laptop and get into the BIOS. There is a screen for brightness. I don't recall how it is labeled, but it's one of the last pages as you cycle through the BIOS options.

The computer is indicating to you that it is unable to detect the presence of the hard drive. You might try booting the computer from the system CD/DVD to repair or restore the drive. (that's what the F12 menu is about) If unable to restore the system, you may need to replace the hard drive.
Any chance that you still have a warranty?

Click Start //Click Control Panel// Performance // screen brightness

you may have damaged the screen in which case theres not much more you can do then replace it.if its a new labtop it may be still under warrenty in which case get back to dell.

Hi there.
Yes, if you can see a very faint image on the screen that indicates that the inverter or inverter coil has become defective and needs looking at or replacing.

Good luck and thanks for using Fixya!!

install keyboard drivers first and try...