HOWTO: UBUNTU view Log Boot Messages

You need to enable boot logging by opening a terminal and typing the following:

$ sudo nano /etc/default/bootlogd

The text editor will open, and the following will be show:

# Run bootlogd at startup ? BOOTLOGD_ENABLE=No

Change BOOTLOGD_ENABLE to yes
Now, everytime you restart, /var/log/boot will be created

Ref: http://ubuntuforums.org/showthread.php?t=49925