Well, I was afraid of his since I'm a newb and all.
 
I just installed my two Msi 580 Lightning cards, now my pc just sits at the "starting windows" screen.
Heres what I did:
1. uninstalled my evga 285 ftw card drivers
2. powered off, unhooked everything from back
3. removed the 285
4. installed the 580's in slot #1 and #3 with my XFi SC in #2 and hooked up the 8pin connectors from power supply and the sli ribbons
5. powered pc up lights and fans come on everything
6. I watched the bootup screen gopast my 759 Classified screen
7. I noticed on my hard drive screen, that only HD #1 and #3 are showing up and I see a yellow word saying "degraded" I guess thats because it doesnt see the #2 HD now??? My HD's were set up in RAID 5(parity). I had someone set this up for me when I built my pc so I have no clue about this. All I know is that all 3 HD's showed up on boot before.
 It went past the "HD screen" and then asked me if I wanted to start windows normally or repair if I added new software or hardware...I picked the 2nd option and thats where I am now. About 30min sitting on the "starting windows" screen.
 
So all you guru's out there HELP!

loveha

Did you check to see if one of your SATA Cables didn't come lose at all during the GPU instal?

 
Thanks it was a loose sata cable, now I;m installing drivers. Fingers crossed!

Glad I could help.
Just one, and no it doesn't matter which way it goes. You can even use the 3-Way SLI Bridge if you have one and want to use that instead.

wanderlai

Well, I guess I didnt disable the onboard graphics on the 759 classified board since its not recognizing the 580's.....guess I'll go ahead and manually download/install the nvidia drivers for the 580. Do I still need to disable the onboard grapics in bios or will the 58o's show up after I install the 580 drivers?

Well at least I'm learning. lol,

There are no on board Graphics for the E759. Or any X58 for that matter. Best bet is to just download the latest drivers for the 580s.