My Laptop: Lenovo Z570, i3 -2348M, 8 GB RAM, 750 GB HDD, Intel HD 3000, nVidia 520M
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Virtualisation is Disabled, npci=0x2000
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I had Mountain Lion on my laptop. I used only npci=0x2000 when i had Mountain Lion.
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I booted once from my USB and saw large black pixels on screen -> I Guessed it as...