If you did not originally have a second Gen SandyBridge processor, your board might not be able to update to the latest BIOS. However, You can try this. If you have ANOTHER computer doesnt matter MAC or Windows based. Download the latest BIOS drivers to a thumbdrive from the ASRock website. boot up into your config screen, and do the instant flash update for the bios. after this, you should be able to get to your post screen. and install windows.
Sucks noone has previously posted to help you. But i hope this helps!