I've setup many dual and more displays but even I am challenged here. Not a word about the PC, OS, card in question and more.
Usually it's just a trip to settings and extend my Windows desktop. In many causes now I find folk using Microsoft drivers which isn't good. So the long answer can't be had here. no details to work with.
So get your drivers from your card from the card maker then let's see you supply the product manual for this card so we can go over how to use it.
I want to use my graphics card HDMI instead of my motherboard cause the motherboard only has 1 and my graphics card has 2 and I need 2 HDMI ports to use my second monitor. I've searched 4 hours, I've talked with different people/geek squad at BestBuy. They want me to pay for them to fix the HDMI but they're not broken for a fact. I've talked to a lot of people and no one seems to know how to do this. Please Help
https://support.hp.com/lt-en/document/c05389962 <--- look here
Operating System: Windows 10 Home 64-bit (10.0, Build 16299)
Language: English (Regional Setting: English)
System Manufacturer: HP
System Model: OMEN by HP Desktop PC 870-2XX
Processor: Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz (4 CPUs), ~3.0GHz
Memory: 8192MB RAM
Available OS Memory: 8128MB RAM
Page File: 5879MB used, 4168MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 12
DX Setup Parameters: Not found
User DPI Setting: 96 DPI (100 percent)
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
Miracast: Available, with HDCP
Microsoft Graphics Hybrid: Not Supported
DxDiag Version: 10.00.16299.0015 64bit Unicode