crwdns2934241:0crwdne2934241:0 mamun6863

crwdns2934249:0crwdne2934249:0:

Try this:

Restart , Hold down CTRL+OPTN+R

it should get into internet recovery, Circling globe and it will end up in disk utility page.

Click on disk utility and erase the hdd from internal only once done go back and go to reinstall Osx sierra.

crwdns2915684:0crwdne2915684:0:

open