Vista - Installation is hung

I am attempting to upgrade Vista Ultimate over XP Professional, SP2. At the
"21% decompressing of files" stage, installation seems to have frozen (8
hours at same place). I clicked the close tab and received a message warning
me that if I closed I may leave my computer in an unusable state. One
article on the Vista help pages suggested that pushing the down arrow would
activate a rollback feature taking me back to my XP OS - this function did
not work. What is the appropriate next step?

Thanks in advance for help...

On Tue, 6 Feb 2007 08:39:02 -0800, u2jimbo
<u2jimbo@discussions.microsoft.com> wrote:

>I am attempting to upgrade Vista Ultimate over XP Professional, SP2. At the
>"21% decompressing of files" stage, installation seems to have frozen (8
>hours at same place). I clicked the close tab and received a message warning
>me that if I closed I may leave my computer in an unusable state. One
>article on the Vista help pages suggested that pushing the down arrow would
>activate a rollback feature taking me back to my XP OS - this function did
>not work. What is the appropriate next step?
>
>Thanks in advance for help...

That's exactly the same point my first attempt to install Vista over
XP Pro SP2 also hung. If you shut down by force (hold the power button
in on your PC until it shuts down) then reboot have waiting 20 seconds
or so you should see a black dual boot screen come up that the Vista
installer put there that hopefully will allow you to get back into XP
without any damage. The old OS hasn't (or shouldn't have been)
replaced at this time.

The "problem" is when you reboot the dual boot screen flys past. You
have literally a few seconds to see it, then quickly use your
keyboard's up arrow key to move up to the XP entry assuming you see
that option. If you don't make it the first time, just keep rebooting
till you make it.

Before trying again, run Update Advisor and even if it says there
should be no problem whatever it lists disable or uninstall. Next
rename any NEW folder your see on your root drive, probably they will
start with a $. I had 3 such folders. These were Vista in limbo. Now
place your Vista disc in your drive and try again. If you resolved
what caused the hang, things should proceed at least past the 21%
point, which seems to be some critial junction for Vista.