Have you tired the normal installation DVD, for example SL-7.3-Install-Dual-Layer-DVD-x86_64.iso, instead of the LiveDVD? Does the Install 
DVD boot correctly?

On 04/20/2017 09:25 PM, James M. Pulver wrote:
> I'm testing the SL7.3 and SL7.2 LiveDVD installer disk and both failed to boot the environment for install on a Dell OptiPlex 755 I'm
> testing, I get a dracut error. The CENTOS7.3 LiveDVD boots to the GUI successfully. Does anyone have any ideas for getting SL7.3 to install
> to this computer? Boot flags or something to the installer DVD? Is this a bug? Let me know the commands or info you need to help with this.
>
> Thanks,