Windows XP help - Critical Update download problem

-----Original Message-----
I have been trying for quite a while, several times, to
download critical update Q817287 and am unable to install
it. This failure happens when I eith accept the download
from automatic updates or if I go onto the microsoft
site. There is no specific error message, just the notice
that it did not install - try again. Any thoughts??
.
Same problem here too. Downloads okay, but install goes
on for over an hour and then sits there even though
indicator is at end. This is on,(so far) 817787 and 331953.