For more information on installing WSUS please check the following link for more information: http://technet.microsoft.com/en-in/library/cc708445(en-us).aspx
Ensure that the advanced synchronization options for express installation files and languages on the old server match the settings on the new server by following the steps below:
To back up updates from file system of old WSUS server to a file, follow these steps:
To restore updates from a file to the file system of the new server, follow these steps:
Note: The WSUS Setup program copies WSUSutil.exe to the file system of the WSUS server during installation. You must be a member of the local Administrators group on the WSUS server to export or import metadata; both operations can only be run from the WSUS server itself and during the import or export process, the Update Service is shut down.
To export metadata from the database of the old Microsoft Windows Server Update Services Server, follow these steps:
To import metadata into the database of the new Microsoft Windows Server Update Services Server, follow these steps:.
Note: It can take from 3 to 4 hours for the database to validate content that has just been imported. Please be patient.
Next we’ll need to change the Group policy and make it point top the new server. To redirect Automatic Updates to a WSUS server, follow these steps:
Note: For more information check http://technet.microsoft.com/en-us/library/cc720539.aspx
The initial settings for access control lists differ between Windows 2000 Server and Windows Server 2003. If you are copying content from Windows 2000 Server to Windows Server 2003, you have to manually add the Network Service group to the access control list for the folder where updates are stored. Give the Network Service group Full Control.
Never import exported data from a source that you do not trust. Importing content from a source you do not trust might compromise the security of your WSUS server.
Note: This information was originally contributed by Sudheesh Narayanaswamy, Support Engineer, on the WSUS Support Team blog: