code 800F0900 Windows update encountered an unknown error

Hi, I have vista ultimate, zone alarm firewall, avg anti virus, windows
defender. The laptop came with a trial version of mcafee, which i have
uninstalled several months ago. Since 19/12/2008 windows updates have failed
with the above error. I have run chkdsk, disk cleanup, but cannot resolve
this issue. Please can you assist?

1. Do Step #2 of this three-step-fix then reboot:
http://service.mcafee.com/FAQDocument.aspx?id=TS100507

2. If no joy, review these previous discussions:

AU Check was withdrawn months ago. Check other threads in that link,
please.

thanks, i've removed mcafee using the removal tool, but still have the error.
I've seen the previous thread for AU Check (v78a)
<http://www.codeplex.com/aureset/Release/ProjectReleases.aspx?ReleaseI...>
but the link does not exist anymore ???. I'm still stuck. Can i get the AU
check exe from another location?

[cfchagas]

hi all

I apparently got rid of the 800F0900 error on my Vista Home Basic by installing Microsoft's System Update Readiness Tool (KB947821) - http://support.microsoft.com/kb/947821

for months, many updates gave me that error, but after installing KB947821, SP2 installation succeeded at first try.

best hopes