Apple :: Macbook - Freeze, And Result In Slowing Other Softwares - Screen Turned Into Blue

I am a macbook user who had my first OS X blue screen. So I installed a new canon printer today, updated ilife 08 to ilife 09(I discovered that the ilife that preinstalled was 08 and the disk that came with macbook was ilife 09, suprise ), and was about to do some software update.

After the software update program checked that there were 6 new updates, it then freeze, and result in slowing other softwares. Then I figured out there is a force quit in apple menu, so I used it and restarted the system. But after the screen turned into blue, it wouldn't respond any more. So I stared at the blue screen for about a minute, and realized that Mac does crash and has blue screen

After anther one minute of waiting, I pushed down the power button and forced the computer to shut down( something I learned from my old Fujitsu laptop, it is one tough laptop, and it lasts for over 8 years already,and still running).

After the computer was restarted, I launched upgrade again, and this time nothing happened. Then I figured out there is something called disk utility that I can use to check the disk, and after the disk permission check, it came back with many permission changes for the canon printer program and some other programs, so I repaired them.