Did you update the Intel driver (from Intel) first?
Laptop graphics update...How to
It's very possible that the Intel graphics are causing the issue...can't tell till you tell us the Intel HD graphics or the exact processor where it can be looked up. https://community.amd.com/thread/190079
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Do you have any yellow marks in Device Manager?
This a followup to the automated response for more detailed info:
These laptops were among the early releases by HP using ATI CCC software with eyefinity. They functioned perfectly outputting to my 3 x 1920x1080 75Hz Dell monitors at 5760x1080.
Everything went sideways after upgrading to windows 10 64bit but I did have eyefinity work for some time until windows update/event changed something. It was not stable thereafter. A clean install of windows made no difference.
Kingfish you are more likely correct that I should look at what windows drivers that were loaded for the Intel integrated graphics chipset. I assumed windows would have got it right since they are so anal with WHQL certified drivers.
I need to find where/how to reload the intel HM55 chipset drivers to see if that rectifies the problem. I know the VGA port on the discrete GPU is not being identified correctly with no EDID info showing in CCC therefore, not allowing for proper GPU scaling. When setting up the desktop properties in CCC I have to go into the VGA Properties screen to deselect the EDID box and reset the resolution to 1920x1080 otherwise it defaults to 1600x900. You would then think that 3 monitors all set to 1920x1080 for 5760x1080 would work....but no. The GPU scaling takes a 5760x1080 images and displays it at 5760x900 I suspect, which is somewhat odd scaling.
So having said all that I will need to investigate what is happing with the VGA graphics port driver info that CCC is using. Again more than likely the intel chipset driver has something to do with it.
Thanks for your advice Kingfish, I will let you know if that is the solution.
If you go to Intel support and run their tool. it should find the chipset drivers..or they are available from HP. A long shot..but easy to check..check the Display/Advanced/Monitor..to see if the monitor is set to 59Hertz instead of the correct 60Hertz. I don't know why or how, but this solved a similar issue in months past.
You mentioned it was after a Windows 10 update that all the problems started. Have you tried to uninstall the Windows updates that you believe started the problem?
If by uninstalling the last Windows Updates solves the problem you can use the attached MS Hide/Unhide to hide the Windows Update from being installed again.
Also I would suggest your upgrade Windows to the latest version in June with the new Windows April Upgrade will be available to download via Windows Update.
Are you able to get 2x1 Resolutions (3840 x 1080) with two Monitors connected using Eyefinity? Just rule out any issues with 3 monitors being connected at the same time.