The story so far... Have an Acer Chromebook 15, entered Dev Mode and have been playing with booting Elementary from a memory stick - decided to install on the hard disc. Downloaded the latest .iso (elementaryos-stable-0.3.1-amd64.20150903.iso - 28/11/15) and rebooted with this, then went through the install process and opted to wipe the Chrome OS (I have a recovery disc and have confirmed that it works).
Installation went fine, rebooted successfully several times, installed Chromium Browser, installed Tweaks (via apt-get) and everything seemed good. Then got a message stating that there were upgrades available (can't now remember where the message came from - might have been the Software Center) - so installed the updates. Message stated that I must reboot to continue update - reboot now or later? Choose reboot now, got the usual 'scary screen', pressed Ctrl-D and that was it - nothing.
Turned it on and off several times - same outcome, nothing happens at all.
I can reboot using the USB stick, but not from the hard disc. I can also get the option to restore the Chrome OS - but it's Elementary I want. Anybody got any ideas as to what I've done wrong and/or any suggestions for a work around? Bob