Problems with GTX580 DCUII or Intel 3000 HD

Hey guys/girls

I recently built my own rig and this is a new thing for me; ie the actual building of a pc and setting everything up. I referred to the guy who sold me parts, builder himself, and forums when I ran into problems but otherwise I highly doubt there was anything wrong with my actual set up of my rig.

Not to waste your guy's time, I'll get to the point. In brief the components of my rig are as follows:

Intel i5 2500K
8GB Dominator GT 1866Mhz
Asus Maximus IV Extreme-Z
Asus GTX580 DCUII
1200W psu
ssd + secondary and tertiary hdd
H100 cooling

When I received the GPU it wasn't plastic sealed like the other components and the packaging also seemed like it was old stock so a thought of skepticism towards the GPU crossed my mind.

Now, after a while of the pc running hundreds, whenever I try to open a game (window's games - haven't installed any proper ones), a message would pop up saying that "no suitable graphics device found". This was intermittent; some days it would come up, other days the programme would open fine. That guy that I know stated that it may be an interference between the discrete gpu and the integrated Intel 3000 HD that comes with the motherboard. He uninstalled Lucid Virtu and everything ran fine again. My gpu widget started showing movement in the usage graph again for the GTX580 etc.

Then after a week the problem came back and when I asked the guy again he told me to disable the 3000 HD in the bios menu. I apologise if this is what to do and I don't know better, as I said I'm a "newbie" and you can slander me with a rig like this but I have my reasons for getting something of this standard.

Back to the point it doesn't seem right to me that an integrated graphics card that was intended to work in conjunction with a discrete card must be disabled for the pc to actually run properly. I don't think the guy has a true understanding of my pc as he's had little experience with the ROG bios (and I understand that, the bios is not conventional).

What I'm asking now is 1) if I must really disable the integrated graphics and if so where in bios do I find that because I tried looking through every single tab there is. And 2) for your guys opinion on this matter as I trust a whole community of knowledge and experience more over someone that I know yes, but not necessarily know much about the components with my rig.

On a side note, I did have my motherboard checked because it gave me prior problems about an USB hub port that my ssd+hdd's never picked up therefore I kept having problems installing Windows initially. It was finally resolved with the report saying that nothing was wrong with my motherboard... also I mentioned the packaging about the GTX580 because I am skeptical about the condition about the gpu and the motherboard. The last thing I want is to have faulty components after everything came to this sort of expense.

Thank you guys in advance and please let me know of your opinions pertaining to the graphics issue.

Kind regards