Here are the steps I used to migrate the VMware Update Manager 5.1 database from local SQL server (2005) to a dedicated 2008 server.

1) Stop the Update Manager Services on the local machine

2) Backup the database, copy to new server then perform a restore. Ensure Overwrite the existing database (WITH REPLACE) is selected

3) Create an SQL login with db_owner permissions. In this example I have created a user called vum_user with DB owner permissions on the Update Manager (VIM_UMDB in my case) and msdb databases.

4) Configure DSN. Update Manager uses a 32 bit DSN so you will need to open up the following program C:\Windows\SysWOW64\obdcad32.exe . 

Change the "Which SQL Server do you want to connect to?" to the new server(eg) dhost.jordansphere.co.uk. Use the details you created in step 3.

5) Execute the folowing C:\Program Files (x86)\VMware\Infrastructure\Update ManagerVMwareUpdateManagerUtility.exe )or wherever Update Manager is installed)

i) Log in using your vCenter Password

ii) Use the sql username/password from step 3 again.

6) When completed start the Update Manager from Services

Note: You may also need to re-enable the plugin if you vSphere Client was conencted throughout this process.