If you have IE8 Beta installed then uninstall it and try again.
If not then see the following
The update is not installed successfully, you receive a message, and the
computer restarts when you try to install an update in Windows Vista:
Please Reply to Newsgroup for the benefit of others
Requests for assistance by email can not and will not be acknowledged.
"Machdel" <Machdel@xxxxxx> wrote in message
> I got Vista Ultimate SP1.
> I never had a problem, but now, for about 2 weeks, my Windows Update is
> running me mad.
> I says, an Update is necessary for further going, it is the Windows Update
> Software 7.2.6001.788.
> Every attempt to install it fails, even when I downloaded the file and tried
> to install it offline.
> I always shows error 8007371C, but there is no information in the help.
> So please help me!