Hi!

I have PC with Intel Core i5 with integrated Intel HD Graphics 530 which supports up to 3 separate displays.
I have connected also Nvidia GeForce GT 710 which supports up to 3 separate displays.
I'm using 6 displays for comfort work, but NEED else one for side info (monitoring tools etc.).
So, I got from friend older Nvidia GeForce 9500 GT which supports up to 2 separate displays + one mirroring.
Problem began after computer start and Windows 10 Enterprise 20H2 disabled all three devices, so I had only single screen.
I tried to update drivers, finished and reboot - even bigger problem - flickering screens and I must to go into safe mode.
There I tried to disallow 9500 GT and reboot. Helped not, even it was disallowed and hardware scan it scans not at boot, but the same problem.
Last chance was to disconnect card from PC and I own very old USB 2.0 to VGA adapter. I used it to reach 7th display.
Problem was with driver - on CD packed with, was old for Windows 7 version 1.0.0. I found update to version 1.0.9 for Windows 8/8.1 and at least it identified device msusb to MS USB 2.0 Display. When I connected VGA cable in display settings was monitor found.
But always at trying to extend desktop it disconnect display. So, I was searching the web and found version 2.0.2 with Windows 10 support. Still was the same problem with disconnecting. So, I tried to install driver from internal list and now I knew what I'm searching, found and updated.
All was looking correctly, desktop extended and after next reboot monitor disappeared from display settings and detection helped not, it is only in device manager.

My Q is very simple:
How to solve two Nvidia graphic cards conflict or USB to VGA problem?

THANK you all for each help, reply or comment.
MiroCan you try to use VGA to HDMI wire and then connect SECOND monitor using HDMI port.
For mirroring, if that works?

All latest CPU units should support it.

For graphics card conflicts CHECK this link
https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/39986/graphics-card-driver-conflict-two-cards-two-driver/
I tried to post it on Nvidia forum and no reply.
I'm sad, I hope that anything is possible to do with clean Windows install and hope it can work.

Problem is that BIOS/UEFI ALLOWS not to disable PCIe port/device, only Device Manager can disable it, but it is no big deal.

If anybody has idea, please help me.

Thank you all.
Miroclean install windows with uefi disabled...Ok, why UEFI disabled?

Miro