All, I've looked at most of the solutions provided here, but still come up with the error above. As for some background, my machine was hijacked by Microsoft with the Windows 10 upgrade and I reverted back to Windows 7 Ultimate, but the Windows Update spins hours upon hours, tying up processor and ram and freezing up browser pages. I took out the SSD (OS) and 'wiped' it with Killdisk on another machine (it has no partitions, so I assume it is clean as if it can right out of the box). Now, when trying to install Win7 Ult with original disk, I get the error above. Things I've tried and done are: Bios is updated, boot order changed to optical first, SSD second, sata cabling changed (devices are recognized in Bios) and moved to various sata ports without any success. My setup is ASUS P55 Extreme, Intel I5-750, 8 gig RAM, bios v 2.7, 120 gig SSD, optical drive. Hard drive (data) is disconnected at this time. I've gone to Boot Menu during POST and selected CD/DVDO-TSSTcorp CDDVDW SH-S2 (my optical drive w Orig Win7 disk) but still come up with the error. Any help from what I described above would be greatly appreciated.