Fresh Install El Capitan

Hi all,
I have been trying to do a clean install of El Capitan on a friend's MacBook Pro late 2011. He has already upgraded but he is curious to see how the process goes with speech as this is his first time on Mac. We started by Command+R and Power Key and waited for sometime until the first screen appears. I remember there were five options, one is the Disk Utility. We chose this and moved to the next page to erase data on the internal HD. Ich7 usb drivers for mac. The usual table of HD's attached to the Mac appear and we selected the one El Capitan is installed on. There has been no erase button, just a page with details about the selected HD. In the Toolbar we found the Erase button and by selecting this we got the message that it can not be erased. I googled for that and found that there are those who faced the same problem and there has been no solution except making sure that there is nothing running while trying to do the clean installation. Could it be VO that prevents us from initialising the installation?? To make sure that we were not doing it the wrong way, I tried with my own Mac Air 2015 and that was different as the erase button in my case was already dimmed. Again, I googled for this and the same recommendation was there to insist on having no processes are to be running while trying to wipe data off on HD. Anyone has suggestion, please?
Thanks.

Clean Install El Capitan Terminal

Fresh Install El Capitan

Fresh Install Of El Capitan On Ssd

Fresh Install El Capitan

OS X El Capitan supports two methods of installation. The default method is an upgrade install, which will upgrade your Mac to El Capitan while preserving all of your user data and apps.This is the most common means of upgrading the operating system and is recommended when your Mac is in good shape and having no problems. Free download font cool jazz apk. Hello, I am fairly new OS X user so I did a lot of install, uninstalls and changed many things on the Yosemite. So I would like to to do a fresh install of El Capitan once it's released. What will be my best option to do it?