The laptop is dual booting with windows 7 and ubuntu 11.10. For 11.10 to boot, I had to add 'nolapic' in GRUB boot options.
I downloaded 12.04LTS LiveCD yesterday and made a CD and a bootable USB stick. With both USB and LiveCD, occasionally I can boot into 12.04. But many times, the boot process stuck at some point.
For USB boot, sometime it works. But other times, it seems to stuck right after seeing the message:
NMI watchdog enabled. takes one hw-pmu counted [0.408590] #2
The number in  changes. Some times it stuck at #2, and sometimes at #3.
For LiveCD boot, sometime it works. But when it stuck, it stuck at different places. At times, the boot process go directly to a blank screen with a blink '_' at up left corner. Sometime it went a bit further, after showing options to try/install ubuntu then stuck with a blank screen with blink '_'.
Anything I can do to get around of this?