Got a Small Business Server 2003 R2 box that started throwing a whole load of errors about Update Services failing and Monitoring not working, neither was the standard MS NTBackup.
Updates Services 3.0 SP2 required an uninstall, then an uninstall of 2003R2 technologies. Followed by a reinstall of both.
Monitoring was straightforward. I ran the configure wizard and told it to reinstall back to default.
The Backup Configuration Wizard was a bit messier. When you ran the wizard and it applied all teh settings, you got the following message at around 75% progress
An unexpected error occurred (80070002)
Googling gave several different suggestions, including reinstall the Admin tools, a hotfix to recreate the MS Integration part of the registry and resetting WMI. None of which fixed the problem. I did notice that the summary configuration page quoted the backup destination as \Backup Files without the drive letter (external USB).
Poking around in the registry uncovered this in HKLM\Software\Microsoft\SmallBusinessServer\Backup but it already included the drive letter. Editing the subkey didn't help.
Deleting the entire key did though. The backup wizard reset and prompted again for the destination drive plus backup exclusions, schedule, etc and completed with error. First backup is running right now ... hurrah