Ok I have so far done ney stop cryptsvc , net stop wuauserv in safe mode, tried renaming SoftwareDistribution to SoftwareDistribution.old and Catroot2.old. Restarted services.

And tried to get this update installed ....... no go.

Stopped the above services again in safe mode, and this time I deleted the contents of SoftwareDistribution folder, and renamed the Catroot2 to Catroot2.old again.

Rebooted tried again, however this update will not install on my desktop, it installed ok on my laptop which is running Vista Home Premium, it is just refusing to play ball on my Vista Ultimate