Recent update Windows Vista – It boots up with the third step 0% (and stop

– I am using an authentic Windows Vista,
– It is running well, until I follows the Windows update and it stops there
forever – third step 0% (over 8 hours!)
– I have checked it the hardware and virus, but all are good.
– I have used the F8 to call boot menu, using the repair option, and boot to
the last known good configuration; all come back to the "update menu : third
step 0%".
– I cannot use safe-mood to go inside the computer, it comes back to this
update process and stop there.

I cannot by-pass this process and uninstall this so-called update! It kills
my computer!

Please help! Trillion Thanks!