I guess that I don't understand...why you are trying to uninstall security updates.
In any case...take a look at Event Viewer and see if you can find any errors that may shed light on your situation.
<<I use a Japanese language system but the error message says (I think) that my user account was denied access. Problem is I am logged in with an Administrator account.>>
I haven't the slightest idea what you are trying to say. What does the above statement...have to do with your inability to install or uninstall Windows critical updates?
Have you tried creating a new user profile with admin privileges...and installing the updates from that account?
Edited by hamluis, 15 December 2009 - 11:03 AM.