i followed this article and i have done all steps.
to enter the ubuntu, just as this article said, i need:
When the Grub menu show up, quickly press “e” to edit the entry (we need to insert the “noapic” flag, else it will lead to kernel panic).
Scroll down to the entry that starts with “vmlinuz” and add “noapic” (without the quotation) at the end of the line, just before the closing quotation marks.
i found a line like this: linux /boot/vmlinuz-3.11.0-15-generic root=UUID=170c9bd7-3e70-4139-bb41-615ad1377168 ro quiet splash $vt_handoff so i add the "noapic" at the end of this line: linux /boot/vmlinuz-3.11.0-15-generic root=UUID=170c9bd7-3e70-4139-bb41-615ad1377168 ro quiet splash $vt_handoff noapic
then i boot into the ubuntu successfully!
BUT, only one time... it means that i did the same "add noapic" thing to boot ubuntu to boot the second time, i just got a black screen... I cant boot into it any more!
it's so weird....
why did it work just one time???
what can I do?