2011 Latitude E6420, Windows 10, brightness keys issue

Flv2358,
Your computer needs Windows 10 drivers. Unfortunately, Dell did not create any Windows 10 drivers for he Latitude E6420 Notebook.

I was having this same exact issue on my E6420 running Win10 Pro

Adjusting the brightness via the FN keys previously worked but stopped randomly working after some time.

Adjusting the brightness still worked in the BIOS.

I installed a previous display driver and tried using the Microsoft Basic Display Adapter; neither worked.

What worked for me:

1. Open Device Manager

2. Click View - Show hidden devices

3. Expanded the Monitors section

4. Deleted ALL "Generic PNP Monitor" devices and one "Generic Non-PNP Monitor" device I had listed.

5. Rebooted laptop

Adjusting the brightness via the FN keys and the Windows Mobility Center works now with no issues.

I chalk my issue up to using SpaceDesk and connecting my laptop via HDMI to my TV.

Thanks! I recall trying that and it sort of worked. The problem was that after the restart the situation was back to "normal" i.e. I had the brightness issue again.

disabling, then re-enabling the display adapter is working for me
(not permanent, will require doing this each time the display brightness keys fail)

to verify if this is working

Find the display adapter in windows system device manager
disable, wait, then re-enable, wait, test your display brightness keys

to automate this (or at least make it much simpler than directly using the system device manager)

I use NirSoft's devmanview (free, no install required, other than to copy the executable to c:\windows directory)
https://www.nirsoft.net/utils/device_manager_view.html

I put this command below into a bat file on the desktop

devmanview /disable_enable "Intel(R) HD Graphics 3000"

then create a shortcut, to run that bat file as administrator

If you have a different display adapter, use the exact name you see in windows device manager, in quotes

Thanks dewslack.  This was an annoying problem when I got my e6420.  This worked for me, I just want to point out to make sure you get the right version of devmanview for your system--32 (x86) or 64 (x64) bit.

Saving a little time when using my laptop, props.

work for me

thanks

10 is not supported but the win7 oem drivers work fine

Using others drivers is NEVER recommended

ONLY WHQL Certified Drivers should be used.

E6420-win7-A08-482C7.CAB

https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=482c7

https://dl.dell.com/FOLDER00949674M/1/E6420-win7-A08-482C7.CAB

is all the drivers for 64 bit and x86

You download the cab file and move to the my documents folder

You then install 7 zip so that you can right click the cab file in mydocuments folder with 7zip and say extract here

https://www.7-zip.org/download.html

I recently began experiencing this issue on my Dell Latitude E6420 running Windows 10 Pro 21H2. I was able to fix it by executing the steps below. You can also see the attached screen capture.

1. Open Device Manager
2. Expand "Display adapters". This reveals that I have the following "Intel(R) HD Graphics 3000" and "NVIDIA NVS 4200M".
3. Right-click on "Intel(R) HD Graphics 3000" and click "Disable device".
4. Click "Yes" when the confirmation prompt appears.
5. After the screen refreshes and Device Manager refreshes, right-click on "Intel(R) HD Graphics 3000" and click "Enable device".
6. After the screen refreshes, you should be able to use the function keys to adjust the screen brightness.