I have upgraded my Ubuntu from 12.04 to 14.04. On the beginning, I had some troubles entering my laptop, but after 2-3 reboots it got working. Anyway, I have used my new 14.04 version fine, and since this mourning I cannot enter my laptop (I have Dell Inspiron 17R - the worst piece of crap I have ever bought, I always have problems with Ubuntu with this laptop). All I can see is this message:
Ubuntu has been blocked by the current security policy
Also, after I click "OK", my laptop cannot boot, it has the message:
Checking media [Fail]
No Boot Device Found. Press any key to reboot the machine
How can I solve this problem? I have very important files on my laptop that I don't want to be lost. Any way I can save my files at least?
Thank you very much in advance for your help.