Sounds like the installation media is faulty. Not too sure where you grabbed it from but you might want to try creating it again, and/or try on a different media, like a different USB or Ext HDD.
If it still persists, you may just want to get a similar computer, install, use a disk imager like Drive Cloner Rx to take an image then just re-image the machine. Tedious and a workaround, but if it persists that's an option.