-- If you have not already done so, try running this command:
Start > Programs > Accessories; right-click Command Prompt and click Run As Administrator. In the window that opens, type: sfc /scannow , then press Enter. Let the SFC (System File Checker) Tool complete, reboot and try installing again.
-- If the above does not work, this Microsoft FixIt may help by repairing corrupted or missing Update components: http://support.microsoft.com/kb/971058
-- If not, then the more thorough Microsoft Vista Update Readiness Tool can be found here: http://www.microsoft.com/download/en/details.aspx?id=504 . It takes a while to finish its work and may look like it's doing nothing. Let it run, reboot and try installing your Updates again.