See: You cannot install some updates or programs
Use the steps for Vista and start with Method 1.
If no joy, go to Method 4, then Method 5.
You can rename the Catroot2 subfolder in Vista if the above Methods fail
to resolve the error, but you must do so from an Elevated Command
Prompt, as described in Method 1:
Start Search text box, right-click cmd.exe, and then click Run as
Use the steps in Method 3 to rename Catroot2 from the Elevated CP.
*** DO NOT RENAME Catroot ***
MowGreen [MVP 2003-2009]