Windows XP critical updates fail to install

[Jack]

I am updating my Windows XP Sp1 regularily with Windows
Update, but recently these systematically fail to
install. it started with 823980, and nothing installs
since then (821557, 819696). They download fine, and
actually do no give an error message during install, but
they do not install, and I can see the installation
failed by viewing the installation history

Anybody who has encountered the same issue and found the
cause and fix ?

 

[Rich Barry]

Take a look here http://v4.windowsupdate.microsoft.com/troubleshoot/

 

[Jack]

Thanks Rich.
I actually checked that site, as I do have error 80070643
in my update.log file, but none of the offerred
suggestion fix the problem, so I'll keep looking.
I also checked the uihist.xml, and it mentions the
errorcode -2147023293.
Thanks for taking the time to post an answer though.