Update and crash

I am a new mac user "3months". It is a great experience and new way to discover this OS and Machine.
I have a 17" macbook pro early 2009 with a leopard and I upgrade it to snow leopard.
Before two or three days I updated the JAVa and the OS to the latest update which is 10.6.2
during the process, I received a msg "update failure" and restart
after restart the screen shows kernel panic screen saying "You need to restart your computer. Hold down the power button for several seconds or press the restart button."
I have Windwos" XP on the bootcampon the same macbook" and i have macdrive on it so i was able to backup 98% of my data except emails on mail program coz i don't know where the mail is stored
kindly, What I need from you here is to help me to repair the system. These cases on i Windows was mostly repaired by reinstalling windows on the same directory in repair mode. I tried to do so by putting the dvd in the laptop and try to use disk utility and a msg said "invalid node structure"
in addition i didn't find anything related to repair in the dvd. either to format or archive!!

if there is anyway not to format the MAc partition by using the ability to use MACDRIVE or any other way i will be more than happy

thanks

Am I doing something wrong? or I didn't ask the right question?
Kindly help me in this issue

Boot the machine from the DVD that came with it. To do so, start machine, insert DVD, restart machine while holding down the C key. When you get to the second install screen go to the toolbar at the top of screen, click utilities then Disc Utility. Run the disc repair and repair permissions. Tell us what it does.

it shows "invalid node structure"

You speak of a MacBook and a MacBookPro - do u have both or just the one Laptop. If u are writing these posts on the MBP then as a easy step try downloading this and running it to see if that sorts the Mac Area