How can i add an Nvidia GPU to my 2 Radeon GPUs

[KT888]

I guess I'll start with... here's my setup
Cooler Master HAF 932, Asrock Z87 OC Formula/ac, 4770K@4.4GHz, Corsair H80i CPU Cooler,
32GB Gskill RipjawsX 2133MHz,
EVGA Supernova P2 1000W 80+ Platinum Fully Modular PSU,
2x Gigabyte 7870 OC GPU,
4x27" BenQ LED

How can i add an Nvidia GPU to my 2 Radeon GPUs.
Right now nothings happening. I installed the GPU and booted up, tried to install the drivers for the GPU and the installer says "Nvidia GeForce Experience requires an Nvidia GPU. ???
Never had this happen before so I'm not sure how to proceed. Why is it not seeing the new GPU.

Thanks

 

[ryguybuddy]

You can't have that. Two AMD cards with a Nvidia card simply don't work. LinusTechTips did a video of SLI/Crossfire in the same build, and it didn't work.

 

[KT888]

I'm not using sli or crossfire.

 

[ryguybuddy]

I'm not using sli or crossfire.

Doesn't matter. You can't mix and match Nvidia and AMD cards. You might as well return the Nvidia GPU. And if your not using Crossfire then why two Radeon GPUs?

 

[KT888]

I already have an AMD and an Nvidia card in one of my other systems and it works fine. It wasn't an issue installing them together either. That's why I'm surprised it's even an issue.
I don't do any gaming. It's for the screen real estate that's it. One of my other systems is down for the count temporarily right now while I wait on a PSU RMA and I was going to use one of the GPUs from it so I'm not down so many screens. Adding this card to this system will add 2 more screens to this system until I get the other one back up and running.