Help! My laptop won't boot after running Windows Update

I was trying to sync my new Microsoft Zune to my laptop and was having
problems loading the driver. On the Microsoft website it said that this might
be solved by running Windows Update. So I did.

Now my laptop won't boot and when I run the system test, the message says:

Root cause found:
Boot critical file C:\Windows\system32\drivers\acpi.sys is corrupt.

Root cause found:
Boot critial file C:\acpi.sys is corrupt.

I'm running preinstalled Windows Vista Home Premium on an HP Pavilion dv9500
laptop.

I know I could reset to factory settings, but I'd like to avoid that if I can

Is/had Automatic Updates been disabled? Have you any idea what update(s)
were installed?
--
~Robear Dyer (PA Bear)
MS MVP-IE, Mail, Security, Windows Desktop Experience - since 2002
AumHa VSOP & Admin http://aumha.net
DTS-L http://dts-l.net/

Phil Welch wrote:
> I was trying to sync my new Microsoft Zune to my laptop and was having
> problems loading the driver. On the Microsoft website it said that this
> might be solved by running Windows Update. So I did.
>
> Now my laptop won't boot and when I run the system test, the message says:
>
> Root cause found:
> Boot critical file C:\Windows\system32\drivers\acpi.sys is corrupt.
>
> Root cause found:
> Boot critial file C:\acpi.sys is corrupt.
>
> I'm running preinstalled Windows Vista Home Premium on an HP Pavilion
> dv9500
> laptop.
>
> I know I could reset to factory settings, but I'd like to avoid that if I
> can