You can try to fix this error by following the instructions that you can find at
http://windows.microsoft.com/en-gb/windows-vista/Windows-Update-error-80070490. A more detailed procedure is described in the Microsoft Knowledge Base article
958044.
You could even download each fix from the Download Center and install each of them manually, one by one, running the installation program as Administrator and restarting your system after each installation (do not forget to disable your antivirus real-time
protection before starting the installations and to re-enable it after completing).
Bye.
Luigi Bruno
