Attempt to dowload Apple free upgrade to Sierra and computer shut down-chimes and will not restart

Attempted to download free upgrade, from Apple, Sierra-went through the motions 1.5 hours later-states restart and I get the chimes and no restart-black screen-i have managed the CPR get in run disc utility many times and shut down restart and nothing again. I can only get a screen on CPR run disc utility states nothing found and Sierra icon faded out so I cannot reload. 21 in flat screen duo core all previous software downloads are current restore option attempted on WDC WD1001FALS-40U9B0 Media, ( whatever this is) and fails (null) error 254