I'm not familiar with the new Ivy Bridge type BIOS but I'm wondering if this isn't some sort of configuration step you've missed. I'm presuming you're still able to run the PC fine by ignoring the error or acknowledging it but you didn't say what it is you do when you get this. In any event, I'd look to see what ASUS utilities you might have installed with the CD that came with it. Since it says "specified OS" this sounds like the something that a builder would configure either in the Ivy Bridge setup or some ASUS utility that runs at startup. You could try the usual by disabling startup items by running msconfig or revisiting the BIOS setup for some missed step. Good luck.