KB Update that checks if SP2 is installed correctly

Hi all

I recently used a nice little utility provided by microsoft through the
windows update, it was KBxxxxxxx.exe

This utility when ran checks whether or not SP2 is installed correctly,
and brings up a dialog box when finished telling you the result.

However I didnt take a note of the number and after spending 2 hours or
searching am pulling my hair out.

Does anybody know the number of this update????

Thanks in advance

Chris Boyle