iMac i7 won't boot after El Capitan install

[djserrone]

i have a 2011 27inch iMac i7 after the install boot of El Capitan my iMac will not boot. I get the grey screen with the apple and the progress bar but the progress bar does't move. I reinstalled from recovery disk and after initial boot after install the same thing - grey screen with the apple and the progress bar but the progress bar does't move/

 

[Patsyx]

I have the same problem with my MacBook Pro. I installed again and now won't shut down till I hear of an update.