Hello, donkd. Thank you very much for taking the time to reach the Intel Communities Team. I will do my best to assist you further.
In order for me to assist you better, please provide me with a DxDiag* report. Please follow these steps to generate it:
1. In the keyboard, press WinLogo key + R.
2. In the Run box please type dxdiag and hit Enter.
3. Click on Save All Information (save it in your desktop).
4. Attach the .txt file that was generated. To attach a file, you must click the “Attach” option on the bottom right-hand corner of the response box.
In addition, please install the latest generic graphics drivers for your system (ver 6136). Click here to download the drivers and, in order to complete the installation, follow the steps listed in this guide: https://www.intel.com/content/www/us/en/support/articles/000005629/graphics-drivers.html
Please be aware that the driver I am sharing with you is a generic driver from Intel® and some features of it might not be available for your machine, we always recommend verifying if there is an update with the manufacturer of the computer. Nevertheless, we can try to perform this troubleshooting step.
Thanks. I thought I had replied to this but see that I apparently did not.
I tried installing the driver you provided, but was unable to do so. Win 10 says I already have the best driver installed, and offers no option to over-ride that. I tried uninstalling the graphics in Device Manager and rebooted, hoping I could install it when the 'new hardware' was found, but the pre-existing driver was loaded, perhaps from Windows' driver cache. No 'new hardware' prompt appeared. I tried replacing the driver as before, with the same result. I 'already have the best driver' according to MS.
I also tried changing the 'Device Installation Settings' under Win10's Advanced System Settings, but that seemed to have no effect whatever.
All steps described were taken while logged on as Administrator.
Finally, here are the diagnostics data attached.
DxDiag.txt.zip 14.1 K
Thank you very much for the attachment, donkd.
In order to successfully install the drivers, please make sure you follow the instructions provided in the video that the link above contains.
You can try as well the graphics drivers provided by HP. Here is the download link: https://ftp.hp.com/pub/softpaq/sp84501-85000/sp84910.exe
Yes, I had already done that. But ever optimistic, I downloaded & ran the HP executable you linked, and it installed the driver 126.96.36.19949, with no change or improvement. Likewise no change after restarting.
I then attempted to install the intel driver 6136 using the Device Manager driver update routine as described in the video. The update fails with the following message: "The best drivers for your device are already installed." There is no option to over-ride. And there was no change.
Both procedures were followed while logged in as administrator.
After my unsuccessful attempts to install the intel driver provided, I found a procedure on the MS site for forcing a driver install.
I followed that procedure and was able to install the driver 6136. Unfortunately, it made no difference, not even after a restart.
Thank you for sharing your findings with us, donkd.
I would like to know which type of cable are you using? Furthermore, have you tried another monitor? Please make sure that your Windows 10* is up to date. You can update your Operating System by running this Microsoft* tool: https://support.microsoft.com/en-us/help/3159635/windows-10-update-assistant
I'm using an HP-branded Displayport to DVI adapter. The monitor has no Displayport.
FWIW, I attached another pc ( XP ) with VGA out to the same monitor, and the display seems flawless. I hope to test the pc with another DVI-capable monitor and other cables today or tomorrow.
To add clarity to my problem, the fault in my display is called posterization, images degraded by reduced colour depth.
The OS is current - Windows 10 Pro version 1803..