You want to recreate the preboot environments in DS 7.1 MR5 or later.
From the Symantec Management Console, click on Settings | All Settings | Deployment and Migration | Symantec Boot Services (PXE) | Preboot Configurations.
Highlight the items you want to recreate and click on "Recreate Preboot Environment". Do NOT click on 'Save Changes'.
In the Windows Task Scheduler, locate NS.Delta Resource Membership Update.
On the Notification Server, locate the Symantec Agent in the systray.
Double click and select Settings.
Click on Update.
Start the Windows Task Manager.
Look for BootWiz.exe.
When the BootWiz is done, the configurations should be updated.
If you have other servers, you may need to repeat the process on each one.