It seems that microsoft has released a version 2 of the update, as you can se
here:
http://support.microsoft.com/kb/941649/en-us
"Known issue
Note This package has been updated to version 2. An issue was identified in
which certain computers that have specific combinations of older AHCI USB
chipsets and CD or DVD drives that use the SerialATA interconnection bus may
not start after the installation of the original version of this package.
Version 2 of this package has removed the fix that caused this problem. If
you are using a computer that experienced this issue, you can restart the
computer by using a bootable Windows Vista DVD and by selecting the
Repair/System Recovery options. If your computer has already installed the
original version of this update and has successfully restarted, you do not
have to install version 2 of this update."
I'm trying to install. ll'see if it works