I know that this solution sucks, but this was the official answer from veritas.
http://support.veritas.com/menu_ddProduct_BEWNT.htm
From Veritas KnowledgeBase
Event ID 7003: This Backup Exec 7.x service depends on the following nonexistant service" comes up during installation of Backup Exec.
TechNote ID: 191580 Last Updated: January 18 2000 05:37 PM
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Symptom:
"Event ID 7003: This Backup Exec 7.x service depends on the following nonexistant service" comes up during installation of Backup Exec.
Solution:
Ensure the following services actually exist in Control Panel - Services :
Service - The name of the service referred to in the error message will be listed in bold italics.
Remote Proceedure Call (RPC) Server - RpcSs
Server - Lanman Server
Workstation - Lanman Workstation
If these do not appear in Services, reinstall Windows NT and the latest Service Pack. These are Windows NT services, and are not installed or modified by Backup Exec. They must exist and be started before Backup Exec will successfully install or execute.