Check in BIOS setup if you have an EFI BIOS. Is there an EFI Boot disk in BIOS boot order? If so remove it and set DVD drive to boot first. Look for another setting for Legacy BIOS to enable. Then wipe the HD with Clean command again and try install.
If no EFI BIOS, reset the BIOS to defaults, set SATA controller at AHCI to try install. Unplug all other HD's and peripherals.
Test your
RAM - Test with Memtest86+ for 5-6 passes. Test your HD with maker's
HD Diagnostic extended CD scan.
Will the disk boot on another PC and see it's HD to prepare for install? If not start over with a new official ISO burned to disk or written to flash stick using Steps 1 and 2 in
Clean Reinstall - Factory OEM Windows 7