This could happen if you failed to properly reinstall the service container. This could also happen if you are impatient like me, and kill the task off before it was finished because of a different issue all together ;-).
Anyhow the resolution is to delete the vzagent user account, then reinstall the service container.
- If you want to fix this issue simply go to START > PROGRAMS > then ADMINISTRATIVE TOOLS. Select the COMPUTER MANAGEMENT option.
- Expand System Tools > Local Users and Groups and select the Users folder.
- Right click on the user vzagent and choose Delete. Confirm you want to Delete the vzagent user.
- Try to reinstall the service container again using the method you tried previously.