New build old OS, no video signal just on onboard mem! Plz help

[BlackSpirit]

New PC build no signal via GPU

I bought 2 r9 290 sapphire tri-x OC
Asus z77 extreme 6 tb4
Corsair 850w
I5 3570k
8gb of hyper x blue

I put it all togheter and made some cable management then i started the system with the monitor dvi port connected to my gpu dvi port. There was no video signal so i switched them still nothing. I connected then my vga cable to the vga port on my mobo and disabled the onboard igpu and set it to use the pci-e in the bios, restarted it and still nothing. The I downloaded the new drivers for mobo and gpu and did the same and still nothing i switched the back and forth I can only run the onboard graphics.

What should i do ? Plz help me

 

[BlackSpirit]

Onboard graphics*

 

[ss202sl]

Install fresh OS. Old OS had drivers from old hardware.

 

[BlackSpirit]

You think that could be the problem Sir? I am rly done whith my nerves and so scared i broke somethink :/

 

[aldan]

ill second doing a fresh install of the os.

 

[BlackSpirit]

Did a new installation of the OS. Still doesn't recognize my vga. When i try to instal my drivers (the new ones from their website) its a fail massage after some time and the installation cancels .

 

[aldan]

go into device manager and find your video card.try updating the driver from there with the driver windows finds.

 

[BlackSpirit]

So i instaled everything, it runed and everything seemed fine. Then i benched heaven with my r9 290 in crossfire and got 82 fps tops. Then i restarted my pc and same problem no video signal agen