Setting up Integraded GPU to use along side Dedicated PCIe GPU

[Gredival]

Do to a limitation of "how many" and "what types of cables/adapters" I have on hand, I'm trying to setup the integrated GPU to be used along side my Dedicated PCI express card, to push a secondary monitor.
The 2 GPu's are a R9 280x and the onboard is a Radeon 3000 series integrated.

Now...the motherboards BIOS actually allows me to enable the onboard GPU even when a dedicated card is plugged in, even stating in the BIOS help menu "enable onboard GPU to be used with a dedicated ATi GPU".

Windows recognizes the onboard GPU in device manager. The device is listed below my dedicated GPU under display adapters. It's titled as Radeon 3000 Series, and NOT showing the yellow exclamation. But under properties, it states no drivers installed for this device. and from what I can tell, not even the "Basic" microsoft video drivers are installed.
The monitor itself remains black screen, and tells me no signal etc.

I am aware that these 2 gpu's have completely different Driver versions. I'm running the lates 6.4.2 hotfix on my 280x, while the last supported version for the 3000 series is Catalyst 13.1 and 13.4Beta(which I downloaded both)
I did manage to manually install the Drivers for the 3000 series after extracting the ATi package to my HDD and updated drivers through device manager (browse for file on my computer yadda yadda)
Once those installed. I had picture on the second monitor, and while it wasnt a clone of the first desktop. It strangely contained it's own startmenu and taskbar icons like the main monitor. Yet I could drag and drop folders and icons from one screen to the next. BUT....there were problems.
I could'nt open the Radeon crimson software, the Aditional Radeon Settings Window as well as, I couldnt access start menu, open windows settings, and a few other major annoyances. It also forced my Main screens resolution from 1920x1080 down to the default res of the second monitor...1600x900. But like I stated above, I couldn't open any windows to any type of system settings. To set it back.
My assumption is the architecture between the 2 GPU's is too different and with 2 different drivers, I'm not going to get this actually working. Perhaps I'm missing something and someone might be able to shed some light on the situation.
My system specs are as follows

Windows 10 Pro Preview 14332
MOBO: Gigabyte 78LMT-USB3 Rev.6
RAM: 16GB
GPU:R9 280x
Integrated GPU: radeon 3000 series

Let me know if you need any more info. And thanks to any help.

 

[Akumajo]

The Radeon HD 3XX0 series has been EOL for many years now preceding the introduction of the cards you have.

Besides driver limitations and support I would recommend looking for the driver release PDFs from ATI/AMD.

Find out the last supported driver for the integrated GPU which has to be whql and you have to manually install that at your risk.

I would use a separate test HHD to find out if it even works with that newer card and if there might be conflicts.

It also means being very careful during driver removal so you don't nuke all Radeon drivers.

I do believe such an idea used to be supported however since the advent of the Radeon HD 5870s and Eyefinity capabilities what you are trying to do is rather redundant although it might work again at your risk.

Also besides driver support differences and hardware capabilities you are trying to use this in Windows 10 which means you have to make sure that the motherboard chipset drivers are properly supported and you aren't losing performance if say you were to do your own analysis of Windows Vista/7 versus Windows 8/10.

 

[Hardwood]

I'm trying to setup the integrated GPU to be used along side my Dedicated PCI express card, to push a secondary monitor.

I must be missing something here. As Akumajo suggests this seems quite redundant when all you need to do is plug both monitors into the 280x.
Once setup use the Action Centre's PROJECT to configure your monitors.