Hello, I have just recently installed Elementary OS freya and everything was working fine until yesterday when I set the default brightness level using the instructions in http://askubuntu.com/questions/66751/how-do-i-set-default-display-brightness and later installing xSwipe touchpad driver just now following the instructions in http://www.elementarynow.com/multitouch-trackpads-luna/ No problems occured on reboot after setting the default brightness level. As I installed the XSwipe and reached the reboot stage of the webpage, my laptop loaded with black screen and no GUI for awhile. I reboot and pressed Alt+F1 to look at the code interface. The first line of the code interface wrote Error "[drm:cpt_serr_int_handler] *ERROR* PCH transcoder A FIFO underrun" When I switch back to the GUI with the E logo, it showed “Disk drive for dev/mapper/cryptswap 1 is not ready yet or not present” I have posted this problem to the Newbie section but no one has replied. I am now logged on using a live USB stick. I want to retrieve my files and data first before doing anything as I have dissertation work on this laptop. I can't move or copy files because the chmod command says I am not allowed to do so even though I have already set terminal to root privileges. Please help.