It should work OHR, what bios version do you have installed?
http://www.msi.com/product/mb/Z77A-GD80.html#/?div=BIOS
*I have the same issue with my z77a-gd80 and it is also supposed to work with IGD
http://www.msi.com/product/mb/Z77A-GD80.html#/?div=BIOS
*I have the same issue with my z77a-gd80 and it is also supposed to work with IGD
