Install Service Packs
Service packs must be installed online on a running Windows installation with the Windows Update Standalone (WUSA) installer. Service packs are provided as .msu files.
To Install a Service Pack
Download the service pack to the computer.
At a command prompt, type the following command.
wusa <path>where
<path>is the full path of the .msu file.
You can also use the /quiet and /norestart options.
See Also
Concepts
Maintenance How-To Topics
Servicing an Image
Install Windows Vista Service Pack 1