Microsoft will deliver SP1 for Windows Vista very soon.
As a prerequisite some updates are needed to ensure that SP1 will actually
install ( this SP switches the complete Kernel in Vista, so this is no
update like all others ) once it is rolled out.

Some people experience issues with those pre-requiste updates which are
delivered via Windows Update automatically now to your PC if it is set to
accept automatic updates.

The problem that will manifest is described here , for example :

[url]http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=2748299&SiteID=17[/url]

The issue which seems to have hit a lot of people that have played with
pre-releases of the SP1 package is that Windows Vista is stuck in a
loophole, trying to install an update,reboots and again tries to install the
update, which then fails each time.
If you shut off your PC at any time then, you have a high risk of seriously
damaging the structure of your Hard Drive.

Therefore the update warns you to not turn off the computer, but again,
Windows itself is stuck there because the (now rtm) version of that update
conflicts with the beta version of that update ( so Vista might very well
"think" it is already installed or something that way )

The only possible solution until now seems to restore the computer back to a
date before that update has shown up in the Download section of your Vista
Box, and to completely remove all Vista Beta SP1 or Beta Updates. (
Control-Panel ->Windows Update, show Installed Updates ) click here
"uninstall" that SP1 related stuff you see in the list.

If you like it or not, but once you are at that loophole where windows vista
cannot install that update, you have no other chance, but to insert your
Vista DVD and boot the PC from that-
Do not choose "install now", but click on the repair Options you will see
located under the Install button, from the menu you will be presented with
you have access to the System restore feature , where you can "go back in
time" to a date before the stuff described here even happenned...

If you have Vista Ultimate or Business and you did a complete PC backup, you
can even restore the complete Hard Drive from the very same menu, once
booted off the DVD.

If you have no restore-points or backups, then chances are extremely high
that you will have to re-install Vista from scratch.

Sorry for my english, I tried to describe it as good as possible, but as a
lot of people experience this, I could imagine these newsgroups here will
soon be full with that topic.


Sascha/germany

more in-detail solution found here for the symptom of "stuck at 0%" :

[url]http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=2849211&SiteID=17[/url]


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1. Boot from Vista DVD (e.g. ensure BIOS is set to boot from CD/DVD).
Note: before the reboot from DVD, they requested that I disconnect attached
peripherals: the printer and the wireless kb/mouse. Plugged in wired
kb/mouse.



2. Select Repair link from the main menu



3. Select to restore to a previous time



4. Restore to a point prior to the offending update



5. Restart normally



6. Launch windows update in vista. Check for updates. Note the important
update that needs to be installed (In this case it was a cumulative update
to Vista Home Premium/Media Center edition) Note the KB# of the update.

In this case it was KB947172: [url]http://support.microsoft.com/kb/947172[/url]



7. Go back to the main windows update screen.



8. Select settings > Turn off automatic updates: Choose "Check for updates
but let me decide when to download/install)



9. Locate and manually download the update based upon the KB# of the update
(in this case KB947172)

[url]http://support.microsoft.com/kb/947172[/url]



10. Turn off virus protection, etc. I have Microsoft Live OneCare. I
disabled virus/spyware.



11. Manually install the downloaded update.



12. The update required a reboot. The now familiary "Step 3 of 3" screen
came up, completed and then loaded the login screen normally (without the
never-ending reboot issue)



13. After desktop loaded normally,

-- Checked Windows update for any important updates (none)

--Enabled automatic updates

--Re-enabled security software (e.g. virus/spyware)



Problem resolved:

This is the text sent by MS Tech support following the incident:



Action:

**********************

John, you tried to install the update KB947172.



Result:

***************************

John, after installing Windows update KB947172 your computer was not booting
to desktop and it was restarting again and again.



Cause:

**************************

Since the Windows registry was corrupted thus windows update application was
not installing the updates automatically.



Resolution:

**********************

We downloaded and installed the update KB947172 manually and after that your
computer was upto date.



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