I had something like this once. I was reinstalling Windows 7, and the installer messed up the disk, after I deleted the existing partitions and selected to install to the empty space. The computer couldn't past POST, I couldn't even go to BIOS.
I had to take out the HDD (it is a laptop), and put it in an USB enclosure. Then, I connected it to another computer (with Windows 7), and went into Disk Management. It appeared as raw, so I formatted it (still in Disk Management), and it worked in the laptop afterwards, no problem at POST.